Etea Mdcat 2010 — Solved Past Paper with Answers

Q1. Mother is _ the baby's dinner in the kitchen.

• A. Preparing✓
• B. Prepared
• C. Preparation
• D. Preparatory

Explanation: The present participle form of "prepare" is "preparing". It is used to describe an action that is ongoing or in progress at the moment of speaking. Therefore, the correct sentence would be: "Mother is preparing the baby's dinner in the kitchen."

Q2. MAKESHIFT is closest in meaning to:

• A. Impulsive
• B. Revolving
• C. Substitute✓
• D. Practical

Explanation: The word "Makeshift" describes something that is improvised or temporary, typically created with limited resources. It is used to describe something that is used as a substitute for something else that is not available or not suitable.

Q3. We were moved _ the cat struggling to save her kitten.

• A. See
• B. Saw
• C. To have seen
• D. To see✓

Explanation: The verb "moved" requires an infinitive complement, and in this sentence, "to see" functions as the infinitive complement. The correct sentence is: "We were moved to see the cat struggling to save her kitten."

Q4. At the eleventh hour means:

• A. One hour before twelve
• B. At the last moment✓
• C. At eleven at night
• D. Eleven hours ago

Explanation: The phrase "at the eleventh hour" is an idiom that means doing something at the last possible moment, just before it is too late. It implies that there is a sense of urgency or a deadline approaching, and that action must be taken immediately to avoid a negative consequence.

Q5. FORESHADOW is closest in meaning to;

• A. Dread
• B. Disguise
• C. Endanger
• D. Indicate✓

Explanation: The "Foreshadow" is closest in meaning to "Indicate". 'Indicate' means to point out, suggest, or show something as a sign or evidence.

Q6. A _ is a person who is dissatisfied and inclined to rebel.

• A. Delinquent
• B. Revolutionary
• C. Pessimist
• D. Nonconformist✓

Explanation: A nonconformist is someone who refuses to conform to established customs, norms, or beliefs of society. They may express their dissatisfaction by challenging traditional ideas or systems and seeking alternative approaches or ideologies. So, this option is correct.

Q7. When everyone hung _ the leader picked on the most suitable person to do the job

• A. Out
• B. About✓
• C. Back
• D. On

Explanation: "About" is the most suitable choice as it conveys the sense of people lingering or being in the vicinity of the leader, waiting for instructions or directions. Therefore, the correct sentence is: "When everyone hung about, the leader picked on the most suitable person to do the job."

Q8. Rashid spoke _ that he was praised by all the debaters.

• A. Well
• B. As well
• C. Very well
• D. So well✓

Explanation: The word "so" is used to intensify the adjective "well". It emphasizes that Rashid spoke exceptionally or impressively, resulting in him being praised by all of the debaters. The sentence could be written as: "Rashid spoke so well that he was praised by all of the debaters."

Q9. The thief ran _ the street to the other side and hid under the bridge.

• A. Over
• B. Across✓
• C. Along
• D. Beside

Explanation: The sentence describes the action of the thief running from one side of the street to the other side and hiding under the bridge. The preposition that fits best is "across", as it implies movement from one side to another.

Q10. A constellation is made up of stars, a troupe is made up of:

• A. Starlets
• B. Speakers
• C. Actors✓
• D. Beggars

Explanation: A constellation is a grouping of stars that forms a pattern or shape in the night sky. It is a term used in astronomy to describe an apparent connection or arrangement of stars as seen from Earth. On the other hand, a troupe refers to a group or company of performers, typically actors, who work together in theatrical or artistic productions. Therefore, the analogy would be that just as a constellation is made up of stars, a troupe is made up of actors.

Q11. He is rather an _ teacher he never accepts the student's excuses.

• A. Incredulous✓
• B. Unbelievable
• C. Interesting
• D. Indiscriminate

Explanation: An incredulous teacher is one who finds it difficult to believe or accept the excuses provided by students. This implies that the teacher is skeptical or doubtful of the validity of the excuses. Hence, the most suitable option is incredulous.

Q12. To have an old head on young shoulders means:

• A. To be wiser than one‘s age✓
• B. To be wiser than one‘s age
• C. To have aches in the shoulders
• D. To be old but appear young

Explanation: The phrase "to have an old head on young shoulders" means "to be wiser than one's age". It means that a person, despite being young, possesses wisdom, maturity, or experience beyond what is typically expected at their age.

Q13. Do you have _ difficulty with the language?

• A. Any✓
• B. Some
• C. Every
• D. Many

Explanation: The word "any" is the appropriate choice because it indicates a lack of specificity or restriction. Therefore, the correct sentence is: "Do you have any difficulty with the language?"

Q14. Here are your shoes,I _ them

• A. Just clean
• B. Just cleaned
• C. Have just cleaned✓
• D. Have just cleaned

Explanation: "Have just cleaned" is the correct option because it uses the present perfect tense, which indicates an action that was completed very recently in the past but has a connection to the present moment. In this case, the action of cleaning the shoes has been completed, and there is relevance to the present moment, which is the shoes being handed over. Therefore, the correct sentence is: "Here are your shoes, I have just cleaned them."

Q15. The stranger _ the little girl with some sweets.

• A. Deceived
• B. Attracted
• C. Enticed✓
• D. Praised

Explanation: Enticed means that the stranger tempted or lured the little girl with the sweets, appealing to her desires or curiosity. Hence, this option is correct.

Q16. The actress traveled _ to avoid being recognized by her fans.

• A. Unknown
• B. Concealed
• C. Incognito✓
• D. Anonymously

Explanation: The word "incognito" means to travel or be in disguise or under an assumed identity to remain anonymous or unrecognized. It is often used to describe a person who wants to hide their true identity, especially celebrities or public figures who wish to avoid attention or maintain privacy. Therefore, the correct sentence is: "The actress traveled incognito to avoid being recognized by her fans."

Q17. You should not swim _ a meal.

• A. After✓
• B. Over
• C. About
• D. Across

Explanation: The phrase "You should not swim after a meal" is a common saying that advises against swimming immediately after eating. Hence, "after" is the correct option.

Q18. He has _ his pen and is buying another one.

• A. Lose
• B. Lost✓
• C. Loser
• D. Loss

Explanation: The sentence indicates that someone has lost their pen and is purchasing a replacement. Therefore, the correct verb form to use is "lost" in the past tense to describe the action of losing the pen. The sentence should be written as: "He has lost his pen and is buying another one."

Q19. The military coup in the country brought an end to _ rule by the emperor.

• A. Omnipotent
• B. Almighty
• C. Dictatorial✓
• D. Monopolistic

Explanation: "Dictatorial" refers to a ruler who exercises absolute or oppressive authority. The phrase "military coup" suggests a forcible seizer of power, often associated with the overthrow of a dictatorial regime.

Q20. Which of the following has four-chambered hearts?

• A. Lizard
• B. Turtle
• C. Crocodile✓
• D. Frog

Explanation: Crocodiles are one of the few reptiles that have a four-chambered heart, similar to that of birds and mammals. Their heart has two atria and two ventricles, which are completely separated by a muscular wall known as the septum.

Q21. The shape of the polio virus is:

• A. Polyhedral shape✓
• B. Bad shape
• C. Tadpole shape
• D. Golf ball shape

Explanation: The polio virus has a polyhedral shape, which means it is roughly spherical with many flat sides or faces. The virus is made up of 60 identical protein units arranged in an icosahedral structure, which gives it its characteristic polyhedral shape. The outer surface of the virus is covered with a protective protein shell, which encases the viral genetic material inside.

Q22. The attachment of two sub-units of ribosomes on a single mRNA is controlled by:

• A. Mg+ ions✓
• B. Na- ions
• C. Proteins
• D. Ribosomal RNA

Explanation: The attachment of two subunits of ribosomes on a single mRNA is controlled by Mg2+ ions.

Q23. An enzyme in the gastric juice of many infant mammals that precipitates milk protein is:

• A. Rennin✓
• B. Pepsinogen
• C. Gastrin
• D. Renin

Explanation: Rennin is an enzyme found in the gastric juice of many infant mammals, including humans, that helps to digest milk proteins. It works by breaking down the protein casein, which is the main protein in milk, into smaller peptides and amino acids. Rennin is produced by specialized cells in the stomach called chief cells.

Q24. Swelling of dead bodies in water is due to:

• A. Osmosis
• B. Diffusion
• C. Expansion
• D. Decomposition✓

Explanation: The swelling of dead bodies in water is primarily due to the process of decomposition. When a body is submerged in water, bacteria and other microorganisms begin to break down the tissues, releasing gases such as methane, hydrogen, and nitrogen. As the gases accumulate, they can cause the body to bloat and swell.

Q25. Equisetum is the living member of:

• A. Sphenopslda✓
• B. Psilopsida
• C. Pteropsida
• D. Lycopsida

Explanation: Equisetum, commonly known as horsetail, is a genus of vascular plants that is a living member of the division Sphenopsida. Sphenopsida is also sometimes called Equisetopsida because it contains only one living genus, Equisetum.

Q26. In hydra, asexual reproduction occurs by:

• A. Binary fission
• B. Budding✓
• C. Sporulation
• D. Fragmentation

Explanation: Hydra reproduces asexually by budding from its body wall.

Q27. During cellular respiration NADH2 produces:

• A. 2 ATP
• B. 3 ATP✓
• C. 4 ATP
• D. 5 ATP

Explanation: During cellular respiration, NADH (nicotinamide adenine dinucleotide) is an important electron carrier that plays a key role in generating ATP (adenosine triphosphate), the primary energy currency of cells. The correct option is:3 ATPExplanation:2 ATP: This option is incorrect. NADH itself does not directly produce ATP; rather, it helps in the process of ATP generation.3 ATP: This option is correct. During cellular respiration, NADH is oxidized, and the electrons it carries are passed through the electron transport chain (ETC) in the inner mitochondrial membrane. As electrons move through the ETC, they release energy, which is used to pump protons (H+ ions) from the mitochondrial matrix to the intermembrane space. This creates an electrochemical gradient across the inner mitochondrial membrane.The flow of protons back into the mitochondrial matrix through ATP synthase harnesses this energy to produce ATP from ADP and inorganic phosphate. For every pair of electrons transferred by NADH through the ETC, approximately 3 molecules of ATP are synthesized. Therefore, each NADH molecule produces around 3 ATP molecules.4 ATP: This option is incorrect. As mentioned earlier, NADH produces approximately 3 ATP molecules, not 4.5 ATP: This option is incorrect. NADH does not produce 5 ATP molecules during cellular respiration. The actual yield is closer to 3 ATP molecules per NADH molecule.In summary, NADH, through its role in the electron transport chain, contributes to the production of approximately 3 ATP molecules per NADH molecule during cellular respiration.

Q28. An individual has an additional sex chromosome which syndrome does it refer to?

• A. Down‘s syndrome
• B. Turner‘s syndrome
• C. Jacobs syndrome
• D. Klinefilter‘s syndrome✓

Explanation: Klinefelter's syndrome is characterized by the presence of an additional X chromosome in males. The typical karyotype is 47, XXY, but variations such as 48, XXXY or 49, XXXXY can also occur.

Q29. HIV is also known as:

• A. AIDS✓
• B. HAV
• C. HTLV
• D. HBV

Explanation: AIDS is merely an advanced form of HIV.

Q30. Smaller the animals:

• A. More rate of respiration✓
• B. Less the rate of respiration
• C. Rate of respiration has nothing to do with the size of animal
• D. None of these

Explanation: The larger the organism, more is the distance covered for the circulation of blood inside the body so more time is taken to circulate blood to every part of the body, which will further affect the heartbeat and also lower the breathing rate, so breathing will be deep, but its rate is slow incase of huge animals like a whale. But, incase of smaller organisms, the blood circulation is faster due to a smaller body, eg. a Shrew or a Rat, since the distance to be travelled by circulating blood will be very less…so, breathing rate will be faster here.

Q31. Which germinal layer develops in the digestive system?

• A. Ectoderm
• B. Mesoderm
• C. Epidermis
• D. Endoderm✓

Explanation: During embryonic development, the digestive system originates from the endoderm, which is one of the three primary germinal layers.

Q32. The center of porphyrin in the head region of hemoglobin is occupied by:

• A. Potassium
• B. Sodium
• C. Magnesium
• D. Iron✓

Explanation: Haemoglobin consists of four polypeptide chains. Each chain is associated with a haem group. Haeme group is an iron-containing group, which consists of porphyrin with a central atom of ferrous (iron) between four pyrrole rings.

Q33. Microsporum furfur causes:

• A. Athletes foot
• B. Ringworm
• C. Dandruff✓
• D. Ergot

Explanation: Microsporum furfur is a type of fungus that is associated with the condition known as dandruff. Dandruff is a common scalp disorder characterized by the shedding of dead skin cells from the scalp, resulting in visible flakes.

Q34. The first crystalline hormone is:

• A. Thyroxine✓
• B. Nor adrenalin
• C. Adrenalin
• D. All of the above

Explanation: Thyroxine, also known as T4, is the first hormone to be identified as a crystalline substance.

Q35. Limbic system in forebrain consists of:

• A. Hypothalamus
• B. Hippocampus
• C. Amygdala
• D. All of the above✓

Explanation: The limbic system is a complex network of brain structures located in the forebrain. Hypothalamus, hippocampus, and amygdala are integral components of the limbic system. They work together to regulate various aspects of emotion, memory, and behavior.

Q36. Which one of the following diseases is due to point mutation?

• A. Down syndrome
• B. Klinefelter syndrome
• C. Phenylketonuria✓
• D. Turner syndrome

Explanation: Phenylketonuria (PKU) is a genetic disorder that is caused by a point mutation, specifically a mutation in a single gene known as the PAH gene.

Q37. Opening of flower buds and leaf buds is called;

• A. Epinasty✓
• B. Thermonasty
• C. Photonasty
• D. Seismonasty

Explanation: Epinasty refers to the downward or outward bending or opening of flower buds or leaf buds. It is a type of tropism, specifically a growth response in which the upper side of the bud or leaf grows slower than the lower side, resulting in the bending or opening of the bud or leaf.

Q38. A cloned baby sheep Dolly was identical to the parent that:

• A. Gave birth to the dolly
• B. Donated reproductive cells
• C. Donated somatic cell✓
• D. Both A and B

Explanation: Dolly, the cloned baby sheep, was created using a somatic cell nuclear transfer (SCNT) technique. The somatic cell, which is a non-reproductive cell from the parent sheep, provided the genetic material that was used to create an identical copy of the parent. Therefore, the cloned baby sheep Dolly was identical to the parent sheep that donated the somatic cell.

Q39. Besides mammalian diaphragm is present in;

• A. Birds
• B. Crocodiles✓
• C. Fishes
• D. Toads

Explanation: Mammals are characterized by a well-developed diaphragm that separates the thoracic chamber from the abdominal cavity. The diaphragm plays an important role in breathing in mammals. Crocodiles also have a well-developed diaphragm. The lung cavity of the crocodile is separated from the rest of the body cavity by a muscular diaphragm. Hence, option B is correct.

Q40. Which one of the following animals has no alimentary canal?

• A. Ascaris
• B. Pinworm
• C. Planaria
• D. Tapeworm✓

Explanation: Tapeworms are parasitic flatworms, they do not possess an alimentary canal.

Q41. All types of plastids are produced from:

• A. Chloroplastids
• B. Proplastids✓
• C. Chromoplastids
• D. Leucoplastids

Explanation: All types of plastids are produced from proplastids. Proplastids are undifferentiated, non-pigmented plastids that serve as the precursor or "stem cell" type of plastids. They can differentiate into various types of plastids based on the specific needs of the plant cell.

Q42. Sperms of which animal can remain viable for years within the female genital tract?

• A. Bat✓
• B. Whale
• C. Camel
• D. Giraffe

Explanation: Bat sperms can remain viable for years within the female genital tract due to their ability to undergo delayed fertilization.

Q43. All of the following plants possess actinomorphic flowers EXCEPT:

• A. Rose
• B. Potato
• C. Apple
• D. Pea✓

Explanation: Peas have zygomorphic flowers with bilateral symmetry, as it does not possess actinomorphic flowers.

Q44. Live attenuated vaccines are used to treat all of the following diseases except:

• A. Typhoid and plague
• B. Polio and measles
• C. Cholera and rabies✓
• D. Mumps and influenza

Explanation: Live attenuated vaccines are designed to provoke a strong immune response by using a weakened form of the virus. They are used for diseases like measles, mumps, and polio. However, cholera and rabies vaccines do not typically use live attenuated strains. Cholera vaccines are usually inactivated, while rabies vaccines are inactivated or recombinant. Understanding the specific vaccines available for each disease is crucial for answering this question correctly.

Q45. Which of the following animals is sedentary in the adult and active in the larval stage?

• A. Sponge✓
• B. Leech
• C. Salamander
• D. Grasshopper

Explanation: Sponges are animals that belong to the phylum Porifera. They have a sedentary or sessile lifestyle in their adult stage and are active in their larval stage.

Q46. Food is preserved in the form of glycogen by:

• A. Plants
• B. Animals✓
• C. Cyanobacteria
• D. Both B and C

Explanation: Glycogen is a complex carbohydrate that serves as a storage form of glucose in animals. It is primarily found in animal tissues, particularly in the liver and muscles. Animals, including humans, store glycogen as a source of energy for future use.

Q47. Urea formation occurs in:

• A. Kidney
• B. Liver✓
• C. Spleen
• D. Lungs

Explanation: b) Liver:This option states that urea formation occurs in the liver. This statement is correct. The liver is the primary site of urea formation in the body. It is an essential part of the process known as the urea cycle, where toxic ammonia (a byproduct of protein metabolism) is converted into urea, a less toxic compound. Urea is then transported to the kidney for excretion in urine.

Q48. The term Gene was coined by:

• A. Johnson✓
• B. Corren
• C. Tschmarch
• D. Purkinje

Explanation: The term "Gene" was coined by the Danish botanist Wilhelm Johannsen. He introduced the term 'gene' in the early 20th century to describe the basic unit of heredity responsible for the transmission of traits from parents to offspring.

Q49. All of the following are gametophyte plants EXCEPT:

• A. Liver wort
• B. Equisetum✓
• C. Funaria
• D. Polytrichum

Explanation: Equisetum, also known as horsetails, are not gametophyte plants. They have a dominant sporophyte stage in their life cycle.

Q50. If the father of a baby is hemophilic and the mother is a carrier then the chances of the baby inheriting the disease will be:

• A. 0%
• B. 50%✓
• C. 75%
• D. 100%

Explanation: If the father has hemophilia and the mother is a carrier, there is a 50% chance that the baby will inherit the disease. Haemophilia is an X-linked genetic disorder, which means it is passed down on the X chromosome. The baby has a 50% chance of inheriting the affected X chromosome from the carrier mother.

Q51. Condensation of chromosomes reaches its peak during early;

• A. Prophase
• B. Metaphase✓
• C. Anaphase
• D. Telophase

Explanation: During the process of cell division, specifically in mitosis or meiosis, condensation of chromosomes occurs. Chromosomes become highly condensed and visible under a microscope during this stage. However, the peak condensation of chromosomes typically occurs during the metaphase stage.

Q52. The hormone that causes seed and bud dormancy in plants is called

• A. Auxins
• B. Ethylene
• C. Abscisic acid✓
• D. Gibberellins

Explanation: Abscisic acid is a plant hormone that plays a crucial role in inducing and maintaining seed and bud dormancy. It is responsible for inhibiting growth and promoting dormancy in plants, especially in adverse environmental conditions.

Q53. Tissue plasminogen activator (TPA) is used for:

• A. Treating anemia
• B. Bone marrow transplant
• C. Dissolving blood clot✓
• D. Treatment of cancer

Explanation: Tissue plasminogen activator (TPA) is primarily used for dissolving blood clots in medical emergencies. TPA is used in conditions such as ischemic stroke, heart attack, and pulmonary embolism, where prompt clot dissolution is necessary.

Q54. Which of the following is present in the center of the Porpyrine ring of chlorophyll?

• A. Iron
• B. Sodium
• C. Potassium
• D. Magnesium✓

Explanation: The porphyrin ring of chlorophyll contains a magnesium atom at its center. Magnesium is a critical component of chlorophyll, responsible for capturing light energy during photosynthesis.

Q55. Which of the following is included in protostome?

• A. Amphioxus
• B. Sea horse
• C. Cheatopterus✓
• D. Sea cucumber

Explanation: Cheatopterus is a genus of trilobite, which is a group of extinct arthropods. Trilobites are examples of protostomes, which represent a major evolutionary branch of bilaterally symmetrical animals.

Q56. Book lungs may be found in which of the following

• A. Clam worm
• B. Spider✓
• C. Silverfish
• D. Leech

Explanation: Book lungs are respiratory organs found in certain arachnids, such as spiders. They are called "book lungs" because their structure resembles a series of pages in a book. These respiratory organs are located in the abdomen of spiders and are used for gas exchange, allowing spiders to breathe oxygen from the surrounding air.

Q57. All cell membranes are composed of:

• A. Proteins
• B. Lipids
• C. Lipo protein✓
• D. Cellulose

Explanation: Lipids → mainly phospholipids, form the bilayer (structural framework).Proteins → embedded or attached, responsible for transport, receptors, enzymes.Together, they form a lipoprotein complex.All cell membranes are composed of lipoproteins (lipids + proteins).

Q58. Who stated this hypothesis? Mosquitoes are involved in the spread of malaria

• A. Ronald
• B. AFA king
• C. Laveran✓
• D. Aristotle

Explanation: Charles Louis Alphonse Laveran, a French physician, was the one who stated the hypothesis that mosquitoes are involved in the spread of malaria. Laveran made this observation in 1880 when he discovered the presence of parasites in the blood of malaria patients and later found the same parasites in the stomachs of mosquitoes.

Q59. The simplest oxygen-producing organisms are:

• A. Photosynthetic bacteria
• B. Autotrophic bacteria
• C. Cyanobacteria✓
• D. Chlamydomenas

Explanation: Cyanobacteria, also known as blue-green algae, are the simplest oxygen-producing organisms. They are a group of photosynthetic bacteria that are capable of carrying out oxygenic photosynthesis.

Q60. Hunger centers are located in;

• A. Hypothalamus✓
• B. Cerebellum
• C. Medulla
• D. Midbrain

Explanation: Hunger centers, which regulate appetite and hunger, are primarily located in the hypothalamus of the brain. The hypothalamus plays a crucial role in regulating various bodily functions, including hunger and satiety.

Q61. Heart muscles are called:

• A. Smooth muscles
• B. Myogenic muscles✓
• C. Striated muscles
• D. Skeletal muscles

Explanation: The heart muscles are called myogenic muscles because they can contract on their own without direct nerve stimulation.

Q62. During the development of the chick peripheral part of the blastoderm lies unseparated from the yolk and forms:

• A. Area pellucida✓
• B. Area opaca
• C. Notochord
• D. Primitive streak

Explanation: During the development of a chick embryo, the peripheral part of the blastoderm that remains attached and unseparated from the yolk forms the Area pellucida.

Q63. An organism that adopts saprophytic mode of nutrition during part of its life is called:

• A. Facultative saprophyte✓
• B. Facultative parasite
• C. Obligate saprophyte
• D. Obligate parasite

Explanation: Saprophytic is the mode of nutrition in which organisms feed on dead and decayed matter, a facultative saprophyte ia a mainly parasitic organism with the ability to survive for a part of its life cycle as a saprophyte, therefore the answer will be A.

Q64. Phloem tissues are composed of:

• A. Tracheids
• B. Trachea
• C. Collenchyma
• D. Sieve tubes✓

Explanation: Phloem tissues are composed of sieve tubes, which are specialized cells responsible for transporting organic materials, such as sugars, throughout the plant. They form the main conducting elements of the phloem.

Q65. Monotropa is a

• A. Total parasite
• B. Total saprophyte✓
• C. Partial parasite
• D. Partial saprophyte

Explanation: Monotropa is a total saprophyte. It obtains its nutrients entirely from decaying organic matter in the soil, and it does not perform photosynthesis as it lacks chlorophyll.

Q66. Extra embryonic membranes like amnion and chorion appeared for the first time in

• A. Fish
• B. Amphibian
• C. Reptiles✓
• D. None

Explanation: Extra embryonic membranes like amnion and chorion appeared for the first time in reptiles. The amnion is a membrane that surrounds and protects the embryo, providing a fluid-filled cavity for its development. The chorion is another extra embryonic membrane that allows for gas exchange with the environment.

Q67. Which one is microsporangium?

• A. Pollen grains
• B. Stamens
• C. Pollen sacs✓
• D. Female cone

Explanation: Pollen sacs, also known as microsporangia, are structures found within the anthers of stamens. They are responsible for producing and containing the microspores, which develop into pollen grains.

Q68. A machine that works like a kidney for the removal of nitrogenous wastes from the blood is called

• A. Lithotipser
• B. Heamometer
• C. Dialyzer✓
• D. None of the above

Explanation: A dialyzer is a machine that functions similarly to a kidney in removing nitrogenous waste from the blood. It is commonly used in medical procedures such as hemodialysis, where it helps filter waste products and excess fluids from the bloodstream when the kidneys are unable to perform this function adequately.

Q69. Yeast belongs to the phylum

• A. Zygomycota
• B. Ascomycota✓
• C. Basidiomycota
• D. Deutromycota

Explanation: Yeasts are unicellular fungi that reproduce asexually by budding. They are commonly classified within the phylum Ascomycota.

Q70. Carotenoid pigments are present in:

• A. Euglenophyta
• B. Pyrrophyta
• C. Chrysophyta
• D. Both A and B✓

Explanation: Euglenophyta, commonly known as euglenoids, are a group of unicellular organisms that possess chloroplasts and are capable of photosynthesis. They contain various pigments, including carotenoids, which contribute to the coloration of these organisms. Pyrrophyta, also known as dinoflagellates, are another group of unicellular organisms. Pyrrophyta also contains carotenoid pigments, which give them their characteristic colors. Therefore, carotenoid pigments are found in both Euglenophyta and Pyrrophyta.

Q71. Salmonella typhosa is a

• A. Coccus bacterium
• B. Bacillus bacterium✓
• C. Spirillus bacterium
• D. Nitrobacterium

Explanation: Salmonella typhosa is the scientific name for the bacillus bacterium responsible for causing typhoid fever, a severe and potentially life-threatening illness. It belongs to the genus Salmonella, which comprises gram-negative bacteria that are rod-shaped or bacillus.

Q72. Increased production of RBCs is called:

• A. Leukaemia
• B. Polycythemia✓
• C. Edema
• D. Anemia

Explanation: Polycythemia is characterized by an abnormally high concentration of red blood cells in the bloodstream.

Q73. Rhythmicity of respiration is maintained by:

• A. The cardiac center
• B. Ventilation center
• C. Pons✓
• D. Carotid sinus

Explanation: The rhythmicity of respiration is primarily maintained by the respiratory centers located in the pons region of the brainstem. In the pons, the pontine respiratory group includes two areas known as the pneumotaxic center and the apneustic center. The respiratory center is responsible for generating and maintaining the rhythm of respiration, and also of adjusting this in homeostatic response to physiological changes.

Q74. Aestivation is also known as:

• A. Spring sleep
• B. Winter Sleep
• C. Autumn sleep
• D. Summer sleep✓

Explanation: Aestivation is a term used to describe a state of inactivity or dormancy that certain animals enter during hot or dry periods, typically in the summer season. It is similar to hibernation but occurs in response to high temperatures or drought conditions rather than cold temperatures. During aestivation, animals may reduce their metabolic rate, seek shelter, and conserve energy until more favorable conditions return. Therefore, aestivation is commonly referred to as "summer sleep."

Q75. All of the following are polysaccharides EXCEPT:

• A. Cellulose
• B. Glycogen
• C. Starch
• D. Lactose✓

Explanation: Lactose is a disaccharide, not a polysaccharide. It consists of glucose and galactose and is commonly found in milk and dairy products.

Q76. Which of the following is a swimming bird?

• A. Penguin✓
• B. Ostrich
• C. Hawk
• D. Kiwi

Explanation: Penguins are swimming birds. They are highly adapted to aquatic life and are known for their ability to swim and drive in the ocean. They have streamlined bodies, webbed feet, and wings modified as flippers, which help them navigate through water.

Q77. Fatty acids are converted into carbohydrates by

• A. Glyoxisome✓
• B. Bile juice
• C. Pancreatic juice
• D. Lysosomes

Explanation: Glyoxisomes are specialized organelles found in plant cells and some microorganisms. They are responsible for the conversion of fatty acids into carbohydrates through a process called the glyoxylate cycle. This cycle allows the utilization of fatty acids as a source of carbon for the synthesis of carbohydrates.

Q78. When the kidney fails to form urine the condition is called

• A. Nephritis
• B. Nephrosis
• C. Ptosis
• D. Anuria✓

Explanation: Anuria is a condition characterized by the absence or significantly reduced production of urine by the kidneys. It indicates the failure of the kidneys to form and excrete urine properly.

Q79. The malarial patient feels chill and fever when:

• A. merozoites increase their population in RBC and burst open the RBC✓
• B. sporozoites enter the bloodstream
• C. sporozoites enter the liver cells.
• D. merozoites come out of the liver cells.

Explanation: During the erythrocytic stage of the plasmodium life cycle, merozoites invade red blood cells and reproduce inside them. As the number of merozoites increases within the RBCs, the RBCs eventually burst open (lysis), releasing more merozoites into the bloodstream. This bursting of infected RBCs leads to the release of toxic substances and triggers an immune response, resulting in symptoms such as chills and fever.

Q80. Which of the following gives a positive test Fehling solution?

• A. Cu (I) oxide
• B. Ethanal✓
• C. Acetone
• D. Phenol

Explanation: Ethanal is an aldehyde and is capable of reducing Cu (ll) ions to Cu (l) ions. It will give a positive test with Fehling's solution.

Q81. A metallic oxide when added to water would most likely form an

• A. Base✓
• B. Acid
• C. Salt
• D. Basic anhydride

Explanation: Metallic oxides that are basic will react with water to form a basic solution. For example, sodium oxide (Na2O) reacts with water to form sodium hydroxide (NaOH), a strong base. Therefore, the most likely product formed when a metallic oxide is added to water is a base.

Q82. Aldehydes may be distinguished from ketones by the use of:

• A. Hoffman reagent
• B. Grignard reagent
• C. Tollens reagent✓
• D. Cannizaro reagent

Explanation: Tollen's reagent, which is a solution of silver nitrate in aqueous ammonia, is used to test for the presence of aldehydes and alpha-hydroxy ketones.

Q83. We used Pb(C2H5)4in the gasoline to reduce:

• A. Consumption of fuel
• B. Price of fuel
• C. The octane number of fueL
• D. Knocking of engine✓

Explanation: The addition of Pb(C2H5)4 in gasoline reduces knocking in the engine by increasing the octane number of fuel. Knocking is caused by premature combustion of fuel, which can damage the engine.

Q84. All of the following tests are used to identify aldehydes except

• A. Talons test
• B. Fehling test
• C. Bacyer test✓
• D. Benedict test

Explanation: Bacyer's test is not used to identify aldehydes. Instead, it is used to detect the presence of unsaturation in organic compounds, such as alkenes and alkynes.

Q85. What is the concentration of [H+] in the HNO3 acid solution with a PH of 3?

• A. 3
• B. -3
• C. - antilog [3]
• D. 10^-3✓

Explanation: pH is defined as the negative logarithm of the hydrogen ion concentration [H+]. Mathematically, it can be expressed as:pH = -log[H+]Rearranging this equation, we get:[H+] = 10-pHSubstituting the given pH of 3 in the above equation, we get:[H+] = 10^-3Therefore, the concentration of [H+] in an HNO3 acid solution with a pH of 3 is 10^-3 M.

Q86. Elements not found in nature synthesized in nuclear reactions and involving the completion of 51 orbital are known as.

• A. Lanthanides
• B. Transition elements
• C. Rate gases
• D. Actinides✓

Explanation: Actinides are a series of chemical elements that span from atomic number 89 (actinium) to 103 (lawrencium) on the periodic table. They are part of the f-block and are characterized by the filling of the 5f orbitals in their atomic structure. Actinides are synthetic elements, meaning they are not found in nature but can be synthesized in nuclear reactions. Completing the 5f orbitals involves the filling of 14 orbitals.

Q87. The Aruba principle governs

• A. Coulomb potential
• B. Vapor pressure
• C. Electronic configuration✓
• D. Entropy

Explanation: The Aruba principle, also known as the Aufbau principle, governs the filling order of atomic orbitals in an atom's electronic configuration. It states that electrons occupy the lowest-energy orbitals first before filling higher-energy orbitals, following a specific order based on the atom's atomic number and the rules of electronic configuration.

Q88. Which one of the following compounds has a sharp melting point?

• A. Pure C6H22O6✓
• B. Impure NaCl
• C. Glass
• D. Mixture of the above two

Explanation: Pure substances generally have sharp melting points. When a pure compound like glucose is heated, it undergoes a phase change from solid to liquid at a specific temperature, resulting in a sharp melting point.

Q89. To distinguish between primary secondary and tertiary alcohol one would use which of the following method:

• A. Witting reaction
• B. Tollen test
• C. Lucas test✓
• D. Ninhydrin test

Explanation: The Lucas test is commonly used to differentiate between primary, secondary, and tertiary alcohols. It involves the reaction of the alcohol with the Lucas reagent, which is a mixture of concentrated hydrochloric acid (HCl) and zinc chloride (ZnCl2). Primary alcohols react slowly, secondary alcohols react moderately, and tertiary alcohols react rapidly to form alkyl chlorides.

Q90. Which of the following functional groups in NOT ortho para directing and activating?

• A. R
• B. OH
• C. COR✓
• D. NH2

Explanation: The acyl group (COR) is not ortho para directing and activating. It is a deactivating group due to the presence of the carbonyl group (C=O), which withdraws electron density from the ring. As a result, the acyl group directs substitution reactions away from the ortho and para positions.

Q91. For the exothermic reaction 2NO(g) → N2(g)+O2(g)

• A. Is independent of temperature
• B. Increases as temperature increases
• C. Decreases as temperature increases✓
• D. Varies with the addition of N2 and O2

Explanation: In general, for an exothermic reaction, the reaction rate decreases as the temperature increases. This is because an increase in temperature provides more energy to the reactant's molecules, leading to a higher number of collisions and more effective collisions.

Q92. Which of the following is NOT a member of transition metal?

• A. Scandium family
• B. Iron family
• C. Titanium family
• D. Beryllium family✓

Explanation: Beryllium (Be) and its family, which includes elements such as magnesium and calcium, are not transition metals. They are located in the s-block of the periodic table.

Q93. Mercury is 13.6 times as dense as water.

• A. Qualitative
• B. Quantitative
• C. Both A and B✓
• D. None of these

Explanation: The qualitative analysis describes the relationship between the densities of mercury and water. It states that mercury is denser than water. Quantitative analysis provides a specific numerical value, 13.6, which represents the ratio of the density of mercury to the density of water. It quantifies the difference in density between the two substances. The statement "Mercury is 13.6 times as dense as water" provides both qualitative and quantitative analysis. Hence, C is the correct option.

Q94. Natural chlorine occurs as a mixture of isotopes if a mixture contains 75% Cl35 and 25% Cl37 what will be its correct atomic weight?

• A. 35.50✓
• B. 34.50
• C. 72.00
• D. 70.00

Explanation: The atomic mass of Cl35 is approximately 35.00 atomic mass units (amu), and the atomic mass of Cl37 is approximately 37.00 amu. To find the atomic weight of the mixture which contains 75% Cl35 and 25% Cl37, we can use the formula:Atomic weight = (abundance of Cl35 × atomic mass of Cl35) + (abundance of Cl37× atomic mass of Cl37)Let's calculate: Atomic weight = (0.75 × 35) + (0.25 × 37) = 26.25 + 9.25= 35.50

Q95. What is the ionic strength of 0.01 M Barium Chloride solution?

• A. 0.03✓
• B. 0.02
• C. 0.04
• D. 0.01

Explanation: We know that:Ionic strength (I) = ½ (m1z1² + m2z2²)Where,m1 = concentration of Ba2+ = 0.01m2 = concentration of Cl- = 0.01 × 2 = 0.02z1 = Charged on Ba2+ = 2z2 = Charged on Cl- = -1Putting the values in the formula of ionic strength, we get:I = ½ (0.01 × 2² + 0.02 × (-1)²)= ½ (0.01 × 4 + 0.02 × 1)= ½ (0.04 + 0.02)= ½ (0.06)I = 0.03

Q96. A group of scientists discovered a new element that gives the properties of inert gases they should palace the new element in the periodic table with the elements of:

• A. s-block
• B. d-block
• C. f-block
• D. p-block✓

Explanation: In the periodic table, elements with similar properties are grouped in blocks based on their electronic configurations. The inert gases, also known as noble gases, are located in the p-block of the periodic table. The p-block elements consist of groups 13 to 18, which include elements such as helium, neon, argon, and so on. These elements have full valence electron shells, making them chemically stable and relatively unreactive. Therefore, when scientists discover a new element that exhibits the properties of inert gases, it should be placed in the p-block of the periodic table.

Q97. Primary cells are used in calculators for long-service life the desirable quality of the cell is:

• A. Low energy densities
• B. No self discharge rates✓
• C. High self-discharge rates
• D. High energy densities

Explanation: A desirable quality of primary cells used in calculators is low or no self-discharge rates, meaning they retain their stored energy for extended periods when not in use. This allows the cell to have a long service life and reduces the need for frequent replacements.

Q98. The formula CH3(CH2)16COO- Na+ represents a member of the class of compounds which are known as:

• A. Steroids
• B. Soaps✓
• C. Carbohydrates
• D. Vitamins

Explanation: The formula CH3(CH2)16COO-Na+ represents a compound known as soap.

Q99. Which of the following groups is considered to have a deactivating effect during aromatic substitution?

• A. –OH
• B. –OR
• C. -NH2
• D. -CN✓

Explanation: -CN (Cyano group) is a deactivating group. It withdraws electron density from the ring through the inductive effect, reducing the reactivity of the system.

Q100. Water has a vapor pressure of 23.75 at 250c what is the vapor pressure of a solution sucrose if its mole fraction is 0.25?

• A. 15.2 torr
• B. 17.8 torr✓
• C. 23.8 torr
• D. 29.7 torr

Explanation: Mole fraction of the solute = xs = 0.25Pressure of the solvent = PH2O = 23.76 torrFirst, we solve for the mole fraction of the solvent.x(H2O) = 1 - 0.25 = 0.75Now, we can solve for the pressure of the solution:P(sol) = (xH2O)(PH2O)= (0.75) (23.76 torr)P(sol) = 17.82 torrTherefore, the vapor pressure of the solution is 17.82 torr.

Q101. Reactant formation in an endothermic reaction would be favored by which of the following?

• A. Increase in temperature✓
• B. Decrease in temperature
• C. No change in temperature
• D. First increase and then decrease in temperature

Explanation: Increasing the temperature of the system provides more heat energy to the reaction, which helps drive the reaction toward the reactant side.

Q102. Chlorofluorocarbons are mainly responsible for:

• A. Air pollution
• B. Water pollution
• C. Acid rain
• D. Ozone layer depletion✓

Explanation: Chlorofluorocarbons (CFCs) are mainly responsible for ozone layer depletion.

Q103. Hydrolysis of Al4C3 gives

• A. CH4✓
• B. C2H6
• C. C3H4
• D. C4H20

Explanation: The hydrolysis of Al4C3 (aluminum carbide) produces methane gas. The chemical equation for the hydrolysis reaction of Al4C3 can be represented as:Al4C3 + 12H2O → 4Al(OH)3 + 3CH4In this reaction, aluminum carbide reacts with water to form aluminum hydroxide and methane gas.

Q104. In which of the following compounds carbon is sp hybridized?

• A. C2H6
• B. C3H6
• C. C4H6✓
• D. C4H8

Explanation: The compound C4H6, also known as butadiene, has four carbon atoms and two double bonds. Each carbon atom is bonded to one hydrogen atom. In butadiene, the carbon atoms involved in the double bonds are sp hybridized.

Q105. The values of ionic product kw are 0.64x10-14 at 180 C, and 1 x 10^-14 at 25 C from this may be derived that

• A. Endothermic process✓
• B. Exothermic process
• C. Vaporization process
• D. Change of H2O into O2 and H2

Explanation: The ionic product of water (Kw) is the product of the concentrations of hydrogen ions (H+) and hydroxide ions (OH-) in water. It is defined by the equation: Kw = [H+][OH-] At 180°C, the value of Kw is given as 0.64×10-14, and at 25°C, it is given as 1×10-14. We know that the value of Kw is temperature dependent. As the temperature increases, the value of Kw also increases. The increase in Kw with increasing temperature is an endothermic process. Endothermic processes absorb heat or energy from the surroundings, increasing the value of Kw.

Q106. If a Cu-bearing material weighing 40g yield 5g Cuo(mw.76.55) the percentage of Cu (at.wt.63.55) in the sample is:

• A. (5x63.55/76.55)/40x100✓
• B. 40/5x79.55/63.x100
• C. 5/40x79.55/63.55x100
• D. 25/40x100

Explanation: To find the percentage of copper (Cu) in the sample, we can use the formula:Percentage of Cu = (Mass of Cu / mass of sample) × 100Given that:Mass of Cu = 5gMass of sample = 40gSubstituting the values into the formula:Percentage of Cu = (5g / 40g) × 100= 5/40×100

Q107. Acids are classified as monoprotic or polyprotic which of the following is a polyprotic acid?

• A. CH3CO2H (aq)
• B. HOCl (aq)
• C. HCHO2
• D. H2CO3✓

Explanation: H2CO3 is a polyprotic acid. It can donate two protons in separate dissociation reactions: H2CO3 ←→ H+ + HCO3- HCO3- ←→ H+ + CO32- These dissociation reactions show that carbonic acid can donate two protons sequentially, making it a polyprotic acid.

Q108. A gas at STP contains only 6.023x1023 atoms and is monoatomic it will occupy

• A. 1.2L
• B. 22.4L✓
• C. 30.5L
• D. 44.8L

Explanation: To determine the volume of the gas at STP (Standard temperature pressure), we can use Avogadro's law, which states that equal volumes of gases at the same temperature and pressure contain an equal number of particles. The gas contains 6.023 × 10²³ atoms, which is equal to Avogadro's number, we can conclude that the gas occupies 1 mole. At STP, 1 mole of any ideal gas occupies a volume of 22.4 liters. This is known as molar volume.

Q109. Carboxylic acid reacts readily with alcohols in the presence of catalytic amounts of mineral acids to yield compounds called

• A. Azides
• B. Esters✓
• C. Ketones
• D. Ethers

Explanation: When carboxylic acids react with alcohols in the presence of catalytic amounts of mineral acids, they undergo an esterification reaction. This reaction results in the formation of compounds known as esters.

Q110. What is the first step taken when metals are obtained from sulphide?

• A. Smelting✓
• B. Reasing
• C. Reduction
• D. Refining

Explanation: When metals are obtained from sulfide ores, the first step is typically smelting. Smelting involves heating the ore in the presence of a reducing agent to convert the metal sulfide into its corresponding metal oxide. This process is often followed by further steps such as reduction, refining, and other purification processes. However, the initial step in obtaining metals from sulfide ores is usually smelting.

Q111. Which of the following is not a polymer?

• A. Plastic
• B. Petroleum✓
• C. Starch
• D. Natural rubber

Explanation: A polymer is a macromolecule made of repeating monomer units. Petroleum (crude oil) is a complex mixture of many different hydrocarbon molecules of various sizes and is not a polymer. Plastic, starch, and rubber are all examples of polymers. Of course. Here are the 40 questions formatted with single empty line spacing to ensure it pastes correctly into your document, with concise, rewritten explanations and renumbered from 61 to 100.

Q112. The device used for the detection of isotopes is

• A. Mass spectrometer✓
• B. Cyclotron
• C. Betatron
• D. Reactor

Explanation: The mass spectrometer is a device commonly used for the detection and analysis of isotopes. It separates ions based on their mass-to-charge ratio, allowing for the identification and quantification of different isotopes in a sample.

Q113. A nucleophile is

• A. Lewis acid
• B. Bronsted acid
• C. Bronsted base
• D. Lewis base✓

Explanation: A nucleophile is a chemical species that donates an electron pair to form a new chemical bond. It is characterized by its electron-rich nature and its ability to participate in nucleophilic reactions. In Lewis acid-base theory, a nucleophile is considered a Lewis base, as it can donate electrons to form a coordinate covalent bond.

Q114. Which of the following ions can act as a Bronsted acid and base in water?

• A. HCO-✓
• B. CN-
• C. NO3-
• D. PO4-

Explanation: The HCO- ion can act as a Bronsted acid by donating a proton to a water molecule, forming H2CO3. It can also act as a Bronsted base by accepting a proton from water, forming H2O and CO32-.

Q115. Which of the following bonds is the least polar?

• A. B....Cl
• B. C….Cl
• C. C….I✓
• D. C….Br

Explanation: CI represents the bond between carbon (C) and iodine (I), which has the least electronegativity, resulting in the least polar bond.

Q116. In which of the following a covatent bond is not likely to exist?

• A. Br
• B. SiF
• C. CaO✓
• D. SeH2

Explanation: A covalent bond is not likely to exist in CaO. Calcium is a metal, and oxygen is a non-metal. When a metal reacts with a non-metal, it typically forms an ionic bond rather than a covalent bond. Therefore, CaO is more likely to have an ionic bond.

Q117. Which of the following oxides has the most basic character?

• A. Na2O✓
• B. MgO
• C. Al2O3
• D. P2O5

Explanation: Sodium oxide is highly basic because it readily releases hydroxide ions when dissolved in water, resulting in a highly alkaline solution.

Q118. Consider a chemical reaction 2Cl(g) → Cl2(g) The extent of completing this reaction depends upon the magnitude of Kc and shows that the equilibrium mixture will consist almost of Cl molecules when:

• A. Kc is very large✓
• B. Kc is very small
• C. Kc is neither very small nor very large
• D. Kc is equal to 1

Explanation: The reaction given is:2Cl(g) \rightleftharpoons Cl_2(g)The equilibrium constant, K_c, is defined as the ratio of the concentrations of the products to the concentrations of the reactants, each raised to the power of their stoichiometric coefficients:K_c = \frac{[Cl_2]}{[Cl]^2} * When K_c is very large: This means that the numerator, [Cl_2], is significantly larger than the denominator, [Cl]^2. In other words, at equilibrium, there will be a much higher concentration of Cl_2 molecules compared to Cl atoms. Thus, the equilibrium mixture will consist almost entirely of Cl_2 molecules.

Q119. Which one of the following characteristics is not usually attributed to ionic substances?

• A. High melting point
• B. Deform when struck
• C. Fragility✓
• D. Crystalline

Explanation: Fragility refers to the tendency of a substance to break or shatter easily. Some ionic substances may be brittle, fragility is not a typical characteristic attributed to them. Fragility is more commonly associated with substances that have weak intermolecular forces or lack a well-defined crystalline structure.

Q120. The bond form between Boron and Hydrogen is:

• A. Ionic
• B. Covalent✓
• C. Coordinate covalent
• D. None of the above

Explanation: Covalent bonds involve the sharing of electrons between atoms. Boron typically forms covalent bonds by sharing electrons with hydrogen.

Q121. Which good quality iron are containing low phosphorus content?

• A. Haematite✓
• B. Limonite
• C. Siderite
• D. Magnetite

Explanation: Haematite is considered a good-quality iron ore because it contains a high percentage of iron and low impurities, including low phosphorous content.

Q122. Which is the correct formula for ammonium carbamate?

• A. H2NCONH2
• B. NH4COONH4
• C. H2NCOONH2
• D. NH2COONH4✓

Explanation: The formula of ammonium carbamate is NH2COONH4.

Q123. Carboxylic acid forms alcohol in the presence of LiAlH4 and the process is:

• A. Reduction✓
• B. Oxidation
• C. Hydrolysis
• D. None of above

Explanation: The process of converting a carboxylic acid into alcohol in the presence of LiAlH4 is reduction. LiAlH4 (lithium aluminum hydride) is a strong reducing agent that can donate hydride ions (H-) to the carboxylic acid, leading to the formation of alcohol.

Q124. Which of the following is NOT considered to be an oxidizing agent?

• A. MnO2
• B. Cl2
• C. NaOH✓
• D. Na2O2

Explanation: NaOH is not an oxidizing agent. It is a strong base that does not readily accept electrons or participate in redox reactions. It can be considered a reducing agent in certain reactions where it donates electrons, but it is not primarily known for its oxidizing properties.

Q125. The instrument that is used to determine the weight of a proton as well as a positive ion and is capable of recording its result as the photograph is called:

• A. Mass spectroscope✓
• B. Atomic spectroscope
• C. Spectrophotographic analyzer
• D. Spectrophotometer

Explanation: A mass spectroscope is an instrument used to determine the weight (mass) of a proton as well as positive ions. It works based on the principle of mass spectrometry, which involves ionizing a sample and separating the ions based on their mass-to-charge ratio. The resulting ion spectrum can be recorded and analyzed.

Q126. Displacement reaction that proceeds by the SN2 mechanism are most successful with compounds that are:

• A. Neopentyl system
• B. Tertiary compound with no branch
• C. Secondary halides
• D. Primary compound with no branch at β– carbon✓

Explanation: Primary compounds with no branching at the β-carbon, are generally the most suitable for SN2 reactions. They have the least steric hindrance, facilitating the attack of the nucleophile from the backside of the carbon and resulting in efficient substitution. Therefore, the most successful compounds for displacement reactions via the SN2 mechanism are primary compounds with no branching at the β-carbon.

Q127. Which is an isomer of ethanol?

• A. CH3OH
• B. C2H5OCH3
• C. CH3OCH3✓
• D. C2H5OC2H5

Explanation: CH3OCH3 is an isomer of ethanol. It is called dimethyl ether, which has the same molecular formula as ethanol but a different structural arrangement.

Q128. In a Galvanic cell, the following reaction takes place: 2H2O ⇋ O2+ 4H+ + 4e it occurs at the

• A. Cathode
• B. Anode✓
• C. External conductor
• D. Cathode and anode

Explanation: In a Galvanic cell, the redox reaction occurs at two different electrodes, the cathode, and the anode. At the cathode, reduction takes place, which involves the gain of electrons. In the given reaction, the reduction-half reaction is:O2 + 4H+ + 4e- → 2H2OAt the anode, oxidation takes place, which involves the loss of electrons. The oxidation-half reaction is:2H2O → O2 + 4H+ + 4e-This is the oxidation reaction (water loses electrons and produces oxygen + protons).Therefore, this reaction occurs at the anode of the Galvanic cell.

Q129. 2.3g of ethanol (C2H5OH) is added to 500g of water to determine the molality of the resulting solution;

• A. 0.01 molal
• B. 0.1 molal✓
• C. 1.1 molal
• D. 1.0 molal

Explanation: Mass of ethanol (solute) = 2.3gMass of water (solvent) = 500gFirst, we need to convert the mass of ethanol to moles. The molar mass of ethanol is approximately 46.07 g/molNumber of moles of ethanol = Mas of ethanol / molar mass of ethanolNumber of moles of ethanol = 2.3 / 46.07 = 0.05 molWe need to convert the mass of water to kilograms. So,Mas of water = 500 g = 500 / 1000 = 0.5 kgFinally, we can calculate the molality of the solution:Molality = Number of moles of ethanol/mass of water in kilogramsMolality = 0.05 mol / 0.5kg = 0.1 mol/kgTherefore, the molality of the resulting solution is 0.1 molal.

Q130. The charge of the electron was determined by the effect of the electric field on the rate of fall of oil droplets under gravity this was done by:

• A. JJ Thomson
• B. E Rutherford
• C. R Milliken✓
• D. WC Roentgen

Explanation: The determination of the charge of the electron using the effect of an electric field on the rate of fall of oil droplets under gravity was performed by American physicist Robert A.Millikan. This experiment is known as the oil drop experiment and was conducted by Millikan in 1909.

Q131. The energy of an electron in the excited state n=4 in hydrogen atom is:

• A. -13.6eV
• B. -3.4eV
• C. -0.85eV✓
• D. -1.5eV

Explanation: The energy of an electron in the excited state with n=4 in a hydrogen atom can be calculated by using the formula for the energy levels of hydrogen:E = -13.6eV / n²Substituting n=4 into the formula, we get:E = -13.6 / (4)²E= -13.6 / 16E = -0.85 eV

Q132. The emission or absorption of energy by an atom is represented by ∆E =

• A. hv✓
• B. ½ mv^2
• C. Mgh
• D. Mc^2

Explanation: The emission or absorption of energy by an atom is represented by: ∆E = hυ Where '∆E' is the energy difference between the initial and final states, 'h' is Planck's constant, and 'υ' is the frequency of the electromagnetic radiation emitted or absorbed. Planck's constant is a physical constant that relates the energy of a photon to its frequency. It is approximately equal to 6.626 × 10-34 joule-seconds.

Q133. The temperature scale which is independent of the nature of the working substance is:

• A. Celsius scale
• B. Fahrenheit scale
• C. Centigrade scale
• D. Thermodynamic scale✓

Explanation: The thermodynamic scale, also known as the absolute temperature scale, is independent of the nature of the working substance.

Q134. Metals are good conductors of electricity because they contain:

• A. Large number of freely mobile electrons✓
• B. A large number of bound electrons
• C. A small number of free electrons
• D. A small number of bound electrons

Explanation: Metals are good conductors of electricity because they contain a large number of freely mobile electrons.

Q135. In alternating current the average value of current in the cycle is;

• A. Zero✓
• B. Constant
• C. Positive
• D. Maximum

Explanation: The average current value in a complete cycle of AC waveform, such as a sine wave, is zero because the positive and negative parts of the waveform cancel each other out.

Q136. The gate which has one input and one output is:

• A. NOT gate✓
• B. AND gate
• C. NAND gate
• D. OR gate

Explanation: A NOT gate, also known as an inverter, has one input and one output. The output of a NOT gate is always the opposite of the input.

Q137. In a transistor, the emitter to base function is:

• A. Reversed biased
• B. Forward biased✓
• C. Neutral
• D. None of these

Explanation: In a transistor, the emitter to base function is forward-biased. A transistor is a three-terminal semiconductor device that can amplify or switch electronic signals. It consists of three layers: the emitter, the base, and the collector. The emitter is doped heavily with impurities to increase its conductivity, while the base is lightly doped. The collector is moderately doped. When a voltage is applied between the emitter and the base, in the forward direction, the emitter-base junction is forward-biased.

Q138. Neutrons can be slowed down if the stationary targets are:

• A. Alpha particles
• B. Photons
• C. Protons✓
• D. Atoms

Explanation: Neurons can be slowed down if they collide with stationary protons. This process is called neutron moderation, and it involves transferring some of the neutron's kinetic energy to the proton. This results in the neutron losing some of its speed or being slowed down.

Q139. If we pass current through the sucrose solution the galvanometer will not show any deflection because sucrose molecules:

• A. Move towards cathode
• B. Move towards anode
• C. React with water
• D. Remain neutral✓

Explanation: Sucrose molecules are electrically neutral, meaning they have an equal number of positive and negative charges. Therefore, when current is passed through a sucrose solution, the molecules will not move towards the cathode or anode, nor will they react with water. As a result, the Galvanometer will not show any deflection. However, if the sucrose solution contains ions or other charged particles, the Galvanometer will show deflection as these charged particles will move toward the oppositely charged electrode.

Q140. To improve the jumping record the long jumper should jump at an angle of:

• A. 30°
• B. 45°✓
• C. 60°
• D. 90°

Explanation: improve the jumping record, the long jumper should jump at an angle of 45°.Here's why:Range of a projectile: The horizontal distance a projectile travels (its range) is maximized when the launch angle is 45 degrees, assuming the launch and landing points are at the same height and air resistance is negligible.Long jump as projectile motion: A long jump can be modeled as projectile motion. The jumper launches themselves at an angle, and their distance is determined by their initial velocity and launch angle.The formula for the range (R) of a projectile is:R = (v₀² * sin 2θ) / gWhere:v₀ is the initial velocityθ is the launch angleg is the acceleration due to gravityThe maximum value of sin 2θ is 1, which occurs when 2θ = 90°, or θ = 45°.While in real-world long jumping, factors like air resistance and the jumper's ability to generate both vertical and horizontal velocity play a role, the optimal theoretical launch angle for maximum distance is still 45°.

Q141. Doppler‘s effect is applicable to:

• A. Sound waves
• B. Light waves
• C. Light waves
• D. Both sound and light waves✓

Explanation: The Doppler effect, named after Austrian physicist Christian Doppler, is the change in frequency or wavelength of a wave about an observer who is moving relative to the source of the wave. It is commonly observed with sound waves, such as the changing pitch of an ambulance siren as it moves towards or away from an observer. The Doppler effect is also observed with light waves, such as the shifting of the spectral lines of stars due to their motion relative to Earth.

Q142. For better resolution and clear visibility through a microscope, we use

• A. Longer wavelength light
• B. Shorter wavelength light✓
• C. Wavelength has no effect
• D. It depends only on the design of the microscope not on light

Explanation: Shorter wavelength light improves resolution and provides clearer visibility through a microscope due to its ability to distinguish smaller details.

Q143. The rest mass energy of the electron is:

• A. 0.51 joule
• B. 1.02 joule
• C. 9.11 x 10^-32 joule
• D. 8.2 x 10^-14 joule✓

Explanation: The rest mass energy of an electron can be calculated using Einstein's equation:E = mc²E = 9.11 × 10-31 × (3 × 108)²E = 9.11 × 10-31 × 9 × 1016E = 9.11 × 9 × 10-15E = 8.19 × 10-14 JE ≈ = 8.2 × 10-14 JSo, the rest mass energy of the electron is approximately 8.2 × 10-14 Joule.

Q144. A charge moving at a relativistic speed has a speed

• A. Equal to the speed of light
• B. Greater than speed of light
• C. Comparable to the speed of light✓
• D. None of these

Explanation: When a charge moves at a relativistic speed, it means it is moving at a significant fraction of the speed of light, approaching but not exceeding it. The speed of the charge would be comparable to the speed of light but always less than it.

Q145. The dimensions of the Planck constant are;

• A. [MLT-2]
• B. [ML2T-1]✓
• C. [MLT-3]
• D. [ML2T-2]

Explanation: Using the SI units for energy (J) and frequency (Hz), the equation is written as:[h] = [E] / [f][h] = [J] / [Hz] Since 1Hz is equivalent to 1/s, the dimensions can be written as:[h] = [J] / [s][h] = [ML²T-2] / [T][h] = [ML²T-1]

Q146. The effect of the decrease in pressure with the increase in speed of the fluid in the horizontal tube gives

• A. Torrielll‘s effect
• B. Bernoulli's effect✓
• C. Venturis effect
• D. Doppler effect

Explanation: Bernoulli's principle states that as the speed of a fluid increases, the pressure exerted by the fluid decreases. This principle applies to the flow of fluids in various situations, including in horizontal tubes. When the fluid flows through a tube and its speed increases, the pressure decreases.

Q147. How much will be the length of a simple pendulum if its period is one second?

• A. 2.5 m
• B. 0.25 m✓
• C. 25 m
• D. 0.025 m

Explanation: The length of a simple pendulum can be calculated using the formula:L = gT² / 4π²Where 'L' is the length of the pendulum, 'g' is the acceleration due to gravity (approximately 9.8 m/s²), and 'T' is the period of the pendulum. Given that the period (T) is one second. Putting the values in the above equation, we get:L = 9.8 × (1)² / 4π²L = 0.248 mL ≈ 0.25 m

Q148. The physical quantity which produces angular acceleration in the body is

• A. Force
• B. Moment of inertia
• C. Impulse
• D. Torque✓

Explanation: Torque is a measure of the force that can cause an object to rotate about an axis. Just as force is what causes an object to accelerate in linear kinematics, torque is what causes an object to acquire angular acceleration

Q149. Which of the following is an example of a vector product of two vectors?

• A. Linear momentum
• B. Angular momentum✓
• C. Force
• D. Electric flux

Explanation: Angular momentum is an example of a vector product of two vectors. The vector product, also known as cross product, is an operation between two vectors that results in a new vector.

Q150. If A = 2i+j+2k then its magnitude is:

• A. 9
• B. 5
• C. 3✓
• D. 1

Explanation: To calculate the magnitude of a vector, we can use the formula:|A| = √(Ax² + Ay² + Az²Where 'A' is the vector and Ax, Ay, and Az are the components of the vector in the x, y, and z directions, respectively.We have,-A = 2i + j + 2kLet's calculate the magnitude:|-A| = √(2)² + (1)² + (2)²= √ (4+1+4)= √(9)= 3Therefore, the magnitude of the vector -A is 3.

Q151. The two metals having the same resistance can be differentiated by their value:

• A. Resistance
• B. Conductance
• C. Temperature coefficient of resistivity
• D. Conductivity✓

Explanation: When two metals have the same resistance, they can be differentiated based on their conductivity. Conductivity is a measure of how easily a material allows the flow of electric current. It is the reciprocal of resistivity.

Q152. When sound waves move from one medium to another medium the quantity which remains unchanged is:

• A. Wavelength
• B. Frequency✓
• C. Speed
• D. Intensity

Explanation: When sound waves move from one medium to another, the quantity that remains unchanged is frequency. Frequency refers to the number of complete oscillations or cycles of a wave that occur per unit of time. When sound waves encounter a change in medium, such as from air to water or from one solid material to another, the frequency of the wave remains the same. This means that the number of oscillations per second does not change.

Q153. The ratio of the capacitance of the capacitor having a dielectric to the capacitance of a capacitor having free space in the dielectric is:

• A. Relative permittivity✓
• B. Permittivity
• C. Permeability
• D. Electric polarization

Explanation: The ratio of the capacitance of the capacitor with a dielectric to the capacitance of the same capacitor with free space is given by the relative permittivity (also known as the dielectric constant) of the material between the capacitor plates. Relative permittivity (εr) = C/Co

Q154. In a step-up transformer when the alternating voltage increases then the alternating current.

• A. Will increase
• B. Will decrease✓
• C. Will not change
• D. None of the above

Explanation: In a step-up transformer, the primary coil has fewer turns than the secondary coil. When the alternating voltage increases in the primary coil, according to Faraday's law of electromagnetic induction, a higher voltage is induced in the secondary coil. However, to maintain the conservation of energy, the current in the secondary coil must be lower than the current in the primary coil. The transformer equation states that the ratio of voltage to current is constant in an ideal transformer: V1/V2 = N1/N2 = I2/I1 Where V1 and V2 are the primary and secondary voltages, N1 and N2 are the number of turns in the primary and secondary coils, and I1 and I2 are the primary and secondary currents. Since the voltage increases in the step-up transformer, according to the transformer equation, the current in the secondary coil will be lower than the current in the primary coil (I1). Therefore, the alternating current will decrease in a step-up transformer when the alternating voltage increases.

Q155. For the production of electromagnetic waves, the charges used are:

• A. Stationary charges
• B. Charges moving with uniform speed
• C. Accelerating charges✓
• D. All of the above

Explanation: Electromagnetic waves are produced when charges undergo acceleration. Acceleration of charges creates changing electric and magnetic fields, which in turn generate electromagnetic waves. Therefore, accelerating charges are necessary for the production of electromagnetic waves.

Q156. The pilot weighting 686N dived down with an acceleration of 9.8m sec-2 its apparent weight is

• A. 343N
• B. 1372 N
• C. 686 N
• D. Zero✓

Explanation: The net force is equal to the sum of the gravitational force and the force due to acceleration:Net force = Gravitational force + Force due to accelerationNet force = 686N + (mass × acceleration)Since the gravitational force is equal to the weight, we have:Net force = Weight + (mass × acceleration)Net force = 686N + (mass × 9.8 m/s²)Now, if the pilot is in free fall with no other external forces acting on them, we can consider the net force to be zero because the gravitational force and the force due to acceleration cancel each other out. Therefore, the apparent weight of the pilot in this scenario is zero.

Q157. The maximum drag force on a sphere falling with zero acceleration is 9.8 N its real weight is:

• A. Zero
• B. 9.8 N✓
• C. 4.9N
• D. 19.6N

Explanation: The drag force experienced by an object falling with zero acceleration is equal to the weight of the object. Therefore, if the maximum drag force on a sphere falling with zero acceleration is 9.8N, its real weight is also 9.8N.

Q158. When the body moves against the force of friction on a horizontal plane, the work done by the body is:

• A. Negative✓
• B. Positive
• C. Zero
• D. Maximum and positive

Explanation: When the body moves against the force of friction on a horizontal plane, the work done by the body is negative. This is because the force of friction acts in the opposite direction of the body's motion. When work is negative, it means that energy is being transferred from the body to the surroundings. In this case, the energy is being dissipated as heat due to the friction.

Q159. In the house circuit, all the electric appliances are connected in parallel between mainline and neutral line appliances will have.

• A. Same current
• B. Same power
• C. Different potential and same current
• D. Same potential difference✓

Explanation: In a parallel circuit, each appliance is connected directly to the main line and the neutral line, creating individual pathways for the current to flow. As a result, the potential difference across each appliance is the same, regardless of the appliance's resistance or power rating.

Q160. A body weighs 72 kg on the surface of the earth its weights on the surface of the moon will be:

• A. 72 kg
• B. 12kg✓
• C. 24 kg
• D. 0kg

Explanation: The weight of an object on the surface of the moon can be calculated using the formula:Weight on the moon = Weight on the Earth× (Acceleration due to gravity on the moon / Acceleration due to gravity on the Earth)The acceleration due to gravity on the moon is about 1/6th of that on Earth.Weight on the moon = 72kg × (⅙)= 12kgTherefore, the weight of the body on the surface of the moon will be 12kg.

Q161. Total confinement of light for propagation in the optical fiber is obtained by:

• A. Total internal reflection
• B. Continuous refraction
• C. Both A and B✓
• D. None of these

Explanation: The total confinement of light for propagation in the optical fiber is obtained through a combination of total internal reflection and continuous refraction. When light travels from a medium with a higher refractive index to a medium with a lower refractive index at an angle greater than the critical angle, total internal reflection occurs. The continuous refraction of the light occurs as it travels through the optical fiber.

Q162. The angle subtended by a vector A = i - j with the x-axis is:

• A. 45 degrees
• B. 135 degrees
• C. 225 degrees
• D. 315 degrees✓

Explanation: To find the angle subtended by a vector A with the x-axis, we can use the inverse tangent function. Given vector: A = i - j Where 'i' and 'j' are the unit vectors along the x-axis and y-axis respectively. The angle θ subtended by vector A with the x-axis can be calculated using the formula: θ = tan-1(Ay / Ax) Where Ay is the y-component of vector A and Ax is the x-component of vector A. In this case, Ay = -1 and Ax = 1 Putting values in the above formula, we get: θ = tan-1(-1/1) = tan-1(-1) = -45° We can convert the angle to its positive equivalent: θ = 360° - |-45°| = 360° - 45° θ = 315°

Q163. Newton's second law of motion establishes a relationship between.

• A. Force and acceleration✓
• B. Mass and force
• C. Mass and velocity
• D. Acceleration and mass

Explanation: Newton's second law of motion states that the acceleration of an object is directly proportional to the net force applied to it and inversely proportional to its mass. Mathematically, it can be expressed as: F = ma This equation shows the relationship between force and acceleration.

Q164. Which of the following is a characteristic of an isothermal change?

• A. Enthalpy is constant
• B. Temperature is constant✓
• C. Pressure is constant
• D. No heat enters or leaves the system

Explanation: An isothermal change refers to a process in which the temperature of a system remains constant throughout the process. In an isothermal change, the system is in thermal equilibrium with its surroundings, meaning there is no temperature difference between the system and its surroundings.

Q165. The traffic signals are red while the eyes are more sensitive to yellow because

• A. Yellow has less speed
• B. Red light refracts less due to its long wavelength✓
• C. Actors
• D. Beggars

Explanation: Red light has a longer wavelength compared to yellow light. Longer wavelengths tend to refract less when passing through mediums like the eye. This means that red light can more easily reach and stimulate the photoreceptor cells in the human eye, making it more visible. On the other hand, yellow light has a shorter wavelength compared to red light. This shorter wavelength causes more refraction when passing through the eye, making it less effective at stimulating the photoreceptor cells. As a result, red light is used in traffic signals to ensure that it can be easily seen, particularly in situations where visibility might be compromised or in low-light conditions.

Q166. The device which can be used for precise measurement of wavelength is

• A. Grating plate
• B. Prism
• C. Polaroid
• D. Michelson interferometer✓

Explanation: The Michelson interferometer is specifically designed for precise measurements of wavelength. It operates based on the interference of light waves and allows for highly accurate determination of wavelength, making it the appropriate choice for this purpose.

Q167. If a tunnel is bored through the center of the earth and a stone is dropped into it, then the

• A. stone will stop at the centre of the earth
• B. stone will move out from the other side of the tunnel
• C. stone will perform simple harmonic motion✓
• D. none of these

Explanation: If a tunnel is bored through the center of the Earth and a stone is dropped into it, the stone will experience the gravitational force pulling it towards the center of the Earth. As it falls toward the center, it will gain speed due to the acceleration of gravity. Once it passes the center, the gravitational force will act in the opposite direction, causing the stone to slow down and eventually start moving back toward the center. This back-and-forth motion resembles simple harmonic motion.

Q168. Gamma rays have high penetrating power than alpha and beta rays due to:

• A. No charge✓
• B. Non-material nature
• C. Small size
• D. Lighter particles

Explanation: Gamma rays have higher penetrating power than alpha and beta particles due to their lack of charge. Alpha and beta particles carry an electrical charge, these charged particles interact more strongly with matter, resulting in shorter penetrating distances. On the other hand, gamma rays are high-energy photons with no charge. They have electromagnetic radiation and do not carry any electrical charge. As a result, they are not repelled or attracted by charged particles and can pass through matter more easily, giving them high penetrating power.

Q169. The heat engine operating in reverse is called:

• A. Electric generator
• B. Refrigerator✓
• C. Carnot engine
• D. Electric motor

Explanation: A heat engine operating in reverse is known as a refrigerator. In a heat engine, work is done on the system to extract heat from a colder reservoir and deliver it to a hotter reservoir. In a refrigerator, the process is reversed, where work is done on the system to transfer heat from a colder space (usually the interior of the refrigerator) to a hotter external environment. Therefore, option b is correct.

Q170. A chemical system is sealed in a strong rigid container at room temp and then heated vigorously change in work done during the process is:

• A. Positive
• B. Negative
• C. Zero✓
• D. Constant

Explanation: Work is defined as the force applied over a distance, resulting in the displacement of an object. In this case, since the container is strong and rigid, it prevents any change in volume or displacement of the chemical system. As a result, the work done on or by the system is zero.

Q171. The capacitive reactance of the AC circuit increases:

• A. By increasing the frequency of AC
• B. By decreasing the frequency of AC✓
• C. Does not depend upon the frequency of the AC voltage
• D. None of these

Explanation: Capacitive reactance (Xc) is inversely proportional to the frequency of the AC voltage. As the frequency decreases, the capacitive reactance increases. The relationship is given by the formula: Xc = 1 / 2πfC Where 'f' is the frequency and 'C' is the capacitance.

Q172. The force exerted on a wire of length one meter carrying a current of one ampere lying normal to the magnetic field is called

• A. Magnetic flux
• B. Magnetic flux density✓
• C. Magnetic permeability
• D. None of these

Explanation: The force exerted on a wire of length one meter carrying a current of one ampere lying normal to the magnetic field is called magnetic flux density.

Q173. The force on an electron in the electric field of 10^8 NC^-1 is

• A. 1.6x10^-4
• B. 1.6x10^-8
• C. 1.6x10^-10
• D. 1.6x10^-11✓

Explanation: The force on an electron in an electric field can be calculated by using the formula:F = qEWhere 'q' is the charge of the electron. The charge of an electron is approximately 1.6 × 10^-19C. Therefore, the force on an electron in an electric field of 10^8 N/C is:F = (1.6 × 10^-19 C) × (10^8 N/C)F = 1.6 × 10^-11 N

Q174. The current produced due to induced emf depends upon

• A. Area of the coil:
• B. Shape of the coil
• C. Turns of coil:
• D. Strength of magnetic field in which coil rotates✓

Explanation: According to Faraday's law of electromagnetic induction, the magnitude of the induced electromotive force (emf) and hence the current produced in a coil depends on the rate of change of magnetic flux through the coil. This rate of change of magnetic flux depends on factors such as the strength of the magnetic field, the area of the coil, and the rate of rotation or change in orientation of the coil with respect to the magnetic field.

Q175. The lifetime of an ordinary excited state is:

• A. 10^-35 sec
• B. 10^-8 sec✓
• C. 10^-3sec
• D. 0.1 sec

Explanation: The lifetime of an ordinary excited state refers to the time it takes for an atom or molecule to transition from the excited state back to the ground state. The average lifetime of most excited states is approximately 10-8 seconds.

Q176. The best shield against X-rays to absorb it is

• A. Lead✓
• B. Steel
• C. Iron
• D. Copper

Explanation: Lead is commonly used as a shield against X-rays due to its high density and high atomic number.

Q177. The minimum number of unequal forces whose vector sum can be zero is

• A. One
• B. Two
• C. Three✓
• D. Four

Explanation: The minimum number of unequal forces whose vector sum can be zero is three. This is known as the triangle law of vector addition. When three forces are properly balanced in magnitude and direction, their vector sum can cancel out to produce a net force of zero. If there were only two unequal forces, their vector sum would never be zero unless they have equal magnitude and opposite directions.

Q178. The dimensions of the gravitational constant are:

• A. [M2L2T]
• B. [M-1L3T-2]✓
• C. [M2L-2T-2]
• D. [ML-2T-1]

Explanation: The dimensions of the gravitational constant can be expressed using the equation for Newton's law of universal gravitation:F = Gm1m2 / r²By rearranging the equation, we can determine the dimensions of G:G = Fr² / m1m2The dimensions of the gravitational constant can be derived as follows:[Force] = [Mass][Acceleration]= [Mass][Length] / [Time]3Substituting the dimensions into the equation:G = ([M][L] / [T]²) × [L]² / [M][M]G = M-1L3T-2

Q179. The wave velocity in any medium depends upon:

• A. Elasticity
• B. Density
• C. Homogeneity
• D. All of the above✓

Explanation: The correct answer is D, "All of the above" because the wave velocity in any medium depends on all of these factors: elasticity, density, and homogeneity. - Elasticity affects how well a material can transmit mechanical waves. More elastic materials allow for faster wave propagation. - Density plays a role because waves travel at different speeds through materials with different densities. For example, sound waves travel faster in denser materials. - Homogeneity refers to the uniformity of a medium. A more homogeneous medium allows for more consistent wave propagation.

Q180. The heating and cooking of food evenly by microwave oven is an example of:

• A. S. H. M
• B. Damped Oscillation
• C. Resonance✓
• D. Free oscillation

Explanation: (a) SHM (Simple Harmonic Motion): Simple Harmonic Motion refers to the back-and-forth motion of an object around a stable equilibrium position. It involves a restoring force that is proportional to the displacement. The heating and cooking of food evenly by a microwave oven does not involve simple harmonic motion. (b) Damped Oscillations: Damped oscillations occur when an object gradually loses energy and comes to rest due to the presence of damping forces like friction or air resistance. The heating and cooking of food by a microwave oven does not involve damped oscillations. (c) Resonance: Resonance occurs when an object or system vibrates at its natural frequency in response to an external force or stimulus. In the case of a microwave oven, it uses electromagnetic waves at a specific frequency to heat and cook food evenly. This process involves the concept of resonance, as the microwaves resonate with the water molecules in the food, generating heat and evenly distributing it. (d) Free Oscillations: Free oscillations refer to the natural oscillations of an object without any external force or damping. The heating and cooking of food by a microwave oven does not involve free oscillations. So, the correct option for the heating and cooking of food evenly by a microwave oven is (c) resonance because it relies on the concept of resonating electromagnetic waves with water molecules to generate heat and cook the food evenly.

Q181. When a body moves in a circle, the angle between its linear velocity and angular velocity is always?

• A. 180°
• B. 0°
• C. 90°✓
• D. 45°

Explanation: The angle between the linear velocity and the angular velocity of a body moving in a circle is 90°.

Q182. Resistive forces are;

• A. Nonconservative✓
• B. Conservative
• C. Both conservative and nonconservative
• D. None of the above

Explanation: Non-conservative forces are those that do work on an object, resulting in dissipation or loss of energy. Resistive forces, such as friction, air resistance, and drag, are examples of non-conservative forces. These forces act opposite to the direction of motion, reducing the kinetic energy of an object.

Q183. The device in which the controlled fission chain reaction is maintained is:

• A. Cyclotron
• B. Betatron
• C. Accelerator
• D. Nuclear reactor✓

Explanation: The device in which the controlled fission chain reaction is maintained is called a nuclear reactor.

Q184. The scientist who was awarded the Noble Prize for explaining the photoelectric effect

• A. Max Planck
• B. Compton
• C. Lousie
• D. Einstein✓

Explanation: Albert Einstein was awarded the Noble Prize in Physics in 1921 for his explanation of the photoelectric effect, which he published in 1905. The photoelectric effect refers to the emission of electrons from a material when it is exposed to light of sufficient energy.

Q185. In CRO the time base circuit is connected to:

• A. Vertical plates
• B. Electron gun
• C. Horizontal plates✓
• D. Fluorescent screen

Explanation: The time base circuit in a CRO is connected to the horizontal plates. These plates control the horizontal deflection of the electron beam, determining the time scale or horizontal position of the displayed waveform. The time base circuit generates a time-varying voltage or current that controls the deflection of the beam across the screen.

Q186. A wire of length 10 cm lying normal to the magnetic field of 0.5T is experiencing a force of 5N. The current in the wire is

• A. 10A
• B. 50A
• C. 100A✓
• D. 500A

Explanation: Given that:Length = L = 10cm = 10 × 10-2 mMagnetic field = B = 0.5TForce = F = 5NCurrent = I =?The force experienced by a current-carrying wire in a magnetic field can be calculated using the formula:F = ILBI = F / LBPutting the values in the above equation, we get:I = 5 / 10× 10-2 × 0.5I = 100 A

Q187. The substances which undergo deformation with a small force are called;

• A. Elastic substances✓
• B. Inelastic substances
• C. Diamagnetic substances
• D. Ductile substances

Explanation: Elastic substances are materials that undergo deformation when subjected to small forces, but they can return to their original shape and size once the force is removed.

Q188. When an alpha particle is emitted by radium 88Ra226 the daughter nucleus is radon the mass number and charge number of which will be:

• A. 90Rn^220
• B. 86Rn^222✓
• C. 89Rn^226
• D. 90Rn^222

Explanation: When an alpha particle is emitted, the mass number of the daughter nucleus will decrease by 4, and the charge number will decrease by 2. Therefore, the resulting radon nucleus will have a mass number of 222 and a charge number of +86, which is 86Rn^222.

Q189. The amount of heat energy required to raise the temperature of a body through 1K is called:

• A. Specific heat
• B. Molar specific heat
• C. Heat capacity✓
• D. Heat of vaporization

Explanation: The amount of heat energy required to raise the temperature of a body through 1 K (or 1 °C) is called:Heat capacity

Q190. The temperature at which the resistance of a conductor approaches zero is called

• A. Normal temperature
• B. Critical temperature✓
• C. Absolute temperature
• D. Curie temperature

Explanation: The temperature at which the resistance of a conductor approaches zero is called the critical temperature.

Q191. The expression for w in the first law of thermodynamics if negative implies all of the following EXCEPT:

• A. Total internal energy has decreased
• B. The system has lost heat
• C. Work done by the system✓
• D. Work done on the system

Explanation: In the first law of thermodynamics, the expression for the change in internal energy of a system can be given as:∆U = Q - WIf the expression for work is negative, it means work is being done by the system rather than on the system. Therefore, the correct option is work done by the system.

Q192. The amount of energy required to break the nucleus into constituent nucleons is called;

• A. Excitation energy
• B. Ionization energy
• C. Binding energy✓
• D. Work function

Explanation: Binding energy is the amount of energy required to break a nucleus into its nucleons (protons and neutrons). It represents the strength of the nuclear forces that hold the nucleons together within the nucleus.

Q193. The turn table is a part of

• A. Spectrometer✓
• B. Telescope
• C. Microscope
• D. Interferometer

Explanation: A spectrometer is an instrument used to measure the properties of light over a specific portion of the electromagnetic spectrum. A turntable is part of a spectrometer that is used to hold a sample and rotate it so that it can be exposed to the light source from different angles. This helps to obtain a more complete analysis of the light spectrum emitted or absorbed by the sample.

Q194. The SI unit of inductance is:

• A. Weber
• B. Weber meter^-2
• C. Tesla
• D. Henry✓

Explanation: Henry is the SI unit of inductance, symbolized by the letter H.

Q195. All of the following are non-renewable resources of energy EXCEPT:

• A. Forests✓
• B. Iron
• C. Petroleum
• D. Natural gas

Explanation: Forests are not considered non-renewable resources of energy. Forests have various uses and can provide energy through biomass, they are renewable resources that can be managed and replenished.

Q196. Which one of the following animals is correctly matched with its one characteristic and the taxon?

• A. Millipede - Ventral Nerve Cord - Arachnida
• B. Sea Anemone - Triploblastic - Cnidaria
• C. Silverfish - Pectoral and Pelvic Fins - Chordata
• D. Duckbilled Platypus - Oviparous - Mammalia✓

Explanation: The duckbilled platypus is a distinctive mammal under the order Monotremata in the class Mammalia. It is oviparous, meaning it lays eggs, a rare trait among mammals.

Q197. Sharks and dogfishes differ from skates and rays because:

• A. Their gill slits are ventrally placed
• B. Their head and trunk are widened considerably
• C. There is distinct demarcation between body and tail
• D. Their pectoral fins distinctly marked off from cylindrical bodies✓

Explanation: The correct answer is that sharks and dogfishes have their pectoral fins distinctly marked off from their cylindrical bodies. This is in contrast to skates and rays, whose pectoral fins are fused with the body, creating a wing-like structure. This distinction is crucial in differentiating these groups within the Chondrichthyes class. The other options are incorrect because they describe features that do not accurately differentiate sharks and dogfishes from skates and rays.

Q198. Which one of the following is one of the paths followed by air or oxygen during respiration in the adult male Periplaneta Americana as it enters the animal body?

• A. Spiracle in metathorax, trachea, tracheloes, oxygen diffuses into cells✓
• B. Mouth, bronchial tube, trachea, oxygen enters cells
• C. Spiracles in prothorax, tracheoles, trachea, oxygen diffuses into cells
• D. Hypopharynx, mouth, pharynx, trachea, tissues

Explanation: The respiratory system of Periplaneta americana, or the American cockroach, is distinct from that of mammals. It consists of a network of tracheae and tracheoles through which air is distributed directly to the cells. Air enters the body through spiracles, small openings on the thorax and abdomen. Specifically, the metathoracic spiracle is one of the primary entry points in the thorax. This system compensates for the cockroach's less efficient circulatory system by directly delivering oxygen to tissues. Other options incorrectly describe a mammalian respiratory path or incorrectly locate the spiracles.

Q199. Pheretima and its close relatives derive nourishment from:

• A. Sugarcane roots
• B. Decaying fallen leaves and soil organic matter✓
• C. Soil insects
• D. Small pieces of fresh fallen leaves of maize, etc

Explanation: The correct answer is that Pheretima and its close relatives derive nourishment from decaying fallen leaves and soil organic matter. Earthworms, including those in the Pheretima genus, are detritivores; they play a role in breaking down and recycling dead plant material, thus improving soil structure and fertility. Other options such as sugarcane roots, soil insects, and fresh leaves do not accurately represent their diet. Earthworms are not equipped to consume live plant roots or soil insects, and fresh leaves are not their primary food source as they prefer decomposed material for easier digestion.

Q200. In which one of the following options are the genus name, its two characters and its phylum not correctly matched?

• A. Pila (i) Body segmented Mollusca (ii) Mouth with radula✓
• B. Asterias (i) Spiny skinned Echinodermata (ii) Water vascular system
• C. Sycon (i) Pore bearing Porifera (ii) Canal system
• D. Periplaneta (i) Jointed appendages Arthropoda (ii) Chitinous exoskeleton

Explanation: The correct answer is Option A. Pila is correctly classified under the phylum Mollusca, but the claim that its body is segmented is incorrect, as molluscs typically have unsegmented bodies. The radula is a characteristic feature of Pila, but the segmentation trait does not apply. In contrast, other options accurately match the genus, traits, and phylum: Asterias has spiny skin and a water vascular system typical of Echinodermata; Sycon has pore-bearing and canal system traits of Porifera; and Periplaneta has jointed appendages and a chitinous exoskeleton characteristic of Arthropoda.