Sindh Mcat Nts 2009 Lumhs — Solved Past Paper with Answers

Q1. Choose the word most similar in meaning to the following:REWARD

• A. Penalty
• B. Prize✓
• C. Sentence
• D. Fine

Explanation: Reward means a thing given in recognition of service, effort, or achievement.Option A is ❌ Penalty means a punishment imposed for breaking a law, rule, or contract; fine.Option B is ✅ Prize has the same meaning of the word reward. It means a thing given as a reward to the winner of a competition.Option C is ❌ Sentence means (noun) a set of words; (verb) the punishment assigned to a defendant found guilty by court.Option D is ❌ Fine means (adjective) of high quality or very thin; (noun) a sum imposed as punishment for an offense.

Q2. Choose the lettered word or phrase that is most nearly opposite in meaning to the following word:SLUGGISH

• A. Slowly
• B. Lively✓
• C. Sleepy
• D. Normal
• E. Wicked

Explanation: Sluggish means slow moving/inactive.Option A is ❌ Slowly is the synonym of sluggish.Option B is ✅ Lively means full of life and energy; active. It is opposite in meaning to sluggish.Option C is ❌ Sleepy needing or ready to sleep. The word sleepy is also used in the meaning of the word sluggish.Option D is ❌ Normal means usual/typical; as expected.Option E is ❌ Wicked means evil or morally wrong.

Q3. Choose the lettered word or phrase that is most nearly opposite in meaning to the following word:ABANDON

• A. Leave
• B. Stop
• C. Throw
• D. Continue✓

Explanation: Abandon means to leave; discontinue/having been deserted.Option A is ❌ Leave means to go away. It is the synonym of the word abandon.Option B is ❌ Stop means to cease or come to an end.Option C is ❌ Throw means to propel through the air by a forward motion of the hand and arm.Option D is ✅ Continue means to keep happening or to resume. It is opposite in meaning to the word abandon.

Q4. Identify the word or phrase that needs to be changed for the sentence to be correct: Never create a promise unless you are certain that you can keep it.

• A. Never
• B. Create✓
• C. You are certain
• D. No Error

Explanation: The correct answer is Option B: Create. The verb 'create' does not fit well in the context of making a promise. A better choice would be 'make' to accurately convey the intended meaning of the sentence. The other options are either correctly used or indicate that there is no error, which is incorrect. 'Never' emphasizes the prohibition effectively, and 'You are certain' expresses assurance appropriately, leaving 'create' as the only term that needs modification.

Q5. Complete the sentence by choosing the most appropriate word:Fish cannot live out _ water.

• A. At
• B. Off
• C. Of✓
• D. For
• E. With

Explanation: Option A is ❌ At is the preposition of time which is use to mention some specific time.Option B is ❌ Off means moving away or to close.Option C is ✅ Of is a function word. Function words are words that exist to explain or create grammatical or structural relationships into which the content of words may fit.Option D is ❌ For is used as a conjunction sometime instead for the word because whereas it is also a preposition of time and place.Option E is ❌ With is a preposition use in the meaning of “having” or “using”.

Q6. Choose the correct option

• A. A thousand million liters of water are delivered to the district daily
• B. Thousand million liters of water are delivered to the district daily
• C. A thousand million liters of water is delivered to the district daily✓
• D. A thousand million liters of water are delivered to the district daily

Explanation: Uncountable noun is a type of noun which cannot be counted and is considered singular. Water is a type of uncountable noun and thus “is” will be used with it so only Option C has “is” used with water so it is correct

Q7. Complete the sentence by choosing the most appropriate word:They went for a walk although it _ raining

• A. Be
• B. Is
• C. Was✓
• D. Has
• E. Had

Explanation: As the sentence is in past indefinite tense so “was” will be used. It is used in first person singular and third person singular

Q8. An object is placed 10 cm in front of a convex mirror of focal length of 20 cm. The distance of the image from the mirror is

• A. 10/3 cm
• B. 20/3 cm✓
• C. 10 cm
• D. 40/3 cm
• E. 25/3 cm

Explanation: See the image below

Q9. A parallel combination of three resistors takes a current of 7.5 A from a 30 V battery. If two of the resistances are 12 Ω and 10 Ω , find the resistance of the third one:

• A. 55Ω
• B. 35Ω
• C. 25Ω
• D. 15Ω✓
• E. 30Ω

Explanation: Image given

Q10. Dimensions of angular momentum are:

• A. MLT
• B. MLT-1
• C. ML2T-1✓
• D. MLT-2
• E. ML

Explanation: See the image

Q11. A ball is thrown vertically upwards with a velocity of 98 m/s. How high does the ball rise three?

• A. 360 meters
• B. 380 meters
• C. 490 meters✓
• D. 510 meters
• E. 320 meters

Explanation: See the image attached

Q12. Three conductors draw respectively currents of 1A, 2A, 4A, when connected in turn across a battery. If they are connected in series across the same battery, the current drawn will be:

• A. 2/7A
• B. 3/7A
• C. 4/7A✓
• D. 5/7A
• E. 9/7A

Explanation: See the image

Q13. Which statement describes the electrical potential difference between two points in a wire carrying a current?

• A. The force required to move a unit positive charge between the points
• B. The ratio of the energy dissipated between the points to the current
• C. The ratio of the power dissipated between the points to the current✓
• D. The ratio of the power dissipated between the points to the charge moved
• E. None of the above

Explanation: As, P=VIV= P/I. Hence option C is correct.

Q14. Which of the following statements about an electric field is incorrect?

• A. The electric field strength due to a point charge varies as 1/r2 where ‘r’ is the distance from the charge.
• B. Electric field strength is a vector quantity.
• C. The electric field strength at a point is a measure of the force exerted on a unit positive charge at that point.
• D. The electric field strength at a point is a measure of the potential gradient at that point.
• E. The electric field strength is zero at all points where the potential is zero.✓

Explanation: All options are correct except Option E ✅.Because the electric field is zero at a particular point, it does not necessarily mean that the electric potential is zero at that point.

Q15. In order for two sound waves to produce beats, it is most important that the two waves:

• A. Have the same frequency
• B. Have the same amplitude
• C. Have the same number of overtones
• D. Have slightly different frequencies✓
• E. Have slightly different amplitudes

Explanation: Option D is correct because inorder to produce an audible beat there must be some difference of frequencies in between the sounds so that they could interfere.

Q16. A camera of 6 inches of focal length is used to photograph a distant scene. The distance from the lens to the image is approximately:

• A. 0.5 ft✓
• B. 1 ft
• C. 2 ft
• D. 4 ft
• E. 6 ft

Explanation: The trick is that you are expected to interpret "distant scene” as an object distance of infinity, in which case the image would form exactly one focal length away on the image side (because that is actually the definition of focal length: rays coming from infinity come to a focus at the focal point). So the distance from the lens to the image would be (approximately) 6 inches.6 inches= 0.5ftSo option A is correct

Q17. Find the angle between two vectors(a=2i+j-3k) and (b=3i-2j-k):

• A. 100°
• B. 70°
• C. 60°✓
• D. 50°

Explanation: Option C is correct.

Q18. For an ohmic conductor, doubling the voltage without changing the resistance will cause the current to:

• A. Decrease by a factor of 4
• B. Decrease by a factor of 2
• C. Remain unchanged
• D. Increase by a factor of 2✓

Explanation: An ohmic conductor follows Ohm's Law which is I ∝ V ==> I = V / R Since resistance remain unchanged and current and potential difference are directly proportional; doubling the voltage will lead to doubling of the current. Since resistance remain unchanged and current and potential difference are directly proportional;doubling the voltage will lead to doubling of the current.

Q19. A vehicle starting from rest attains a speed of 72 km/h after covering a distance of 100m. If the mass of the vehicle is 500 kg; find the force exerted by the engine?

• A. 250 N
• B. 500 N
• C. 750 N
• D. 1000 N✓
• E. 1250 N

Explanation: The correct option is D

Q20. A string, fixed at both ends, has a length of 6 m and supports a standing wave with a total of 4 nodes. If a transverse wave can travel at 40 m/s down the rope, what is the frequency of this standing wave?

• A. 6.7 Hz
• B. 10.0 Hz✓
• C. 13.3 Hz
• D. 20.0 Hz
• E. 26.7 Hz

Explanation: The correct option is B

Q21. X,Y and Z are unit vectors and are perpendicular to each other, then which of the following is correct ?

• A. x.x = y.y = z.z = 1
• B. x.y = y.z = z.y = 1
• C. z.x = y.z = x.y = 1
• D. x.x = y.z = z.x = 0
• E. Both (x.x = y.y = z.z = 1) and (x.y = y.z = z.x = 0)✓

Explanation: The correct option is E

Q22. Two capacitors of capacitance C1 and C2 are connected in parallel.If the charge ‘O’ is given to the assembly, it gets shared. The ratio of the charge on the capacitor C1 to the charge on capacitor C2 is given by:

• A. C1/C2✓
• B. C2/C1
• C. (C12) / (C22)
• D. (C22) / (C12)
• E. (C22) / 2C2

Explanation: The correct option is A

Q23. What is the takeoff speed of a locust if it’s launch angle is 55 ̊ and it’s range is 0.8 ? (g=9.8 m/s2)

• A. 1.77 m/s
• B. 2.89 m/s✓
• C. 3.11 m/s
• D. 4.24 m/s
• E. 5.59 m/s

Explanation: As velocity is approximately equal to 2.89m/s so the correct option is B

Q24. A plane travels from point ‘A’ for 1 hour towards the west at 400 km/h and then travels towards the North for 1 hour at 300 km/h arriving at point ‘B’. A second plane starting at ‘A’ at the same time as the first plane and traveling towards ‘B’ along a straight line will arrive at ‘B’ at the same time as the first plane if it’s speed is:

• A. 100 km/h
• B. 250 km/h✓
• C. 500 km/h
• D. 700 km/h
• E. 1200 km/h

Explanation: The correct option is B

Q25. Two springs fixed at one end are stretched by 5 cm and 10 cm, respectively, when masses 0.5 kg and 1 kg are suspended at their lower ends. When displaced slightly from their mean positions and released, they will oscillate with time periods in the ratio

• A. 1:√2✓
• B. 1:2
• C. 2:1
• D. √2:1

Explanation: This is the correct answer. The time period of a spring-mass system is given by T = 2π√(m/k), where T is the time period, m is the mass, and k is the spring constant. Since the spring constant is the same for both springs (as the same force produces the same extension), the ratio of the time periods will only depend on the ratio of the masses: T1/T2 = √(m1/m2). Substituting the given masses, we get T1/T2 = √(0.5 kg / 1 kg) = √(1/2) = 1/√2.

Q26. Recently the phenomenon of superconductivity has been observed at 95 K. This temperature is nearly equal to:

• A. -288 °F✓
• B. -146 °F
• C. -368 °F
• D. +178 °F
• E. -202 °F

Explanation: The correct option is A

Q27. Light passes through two parallel slits and falls on a screen. The pattern produced is due to interference and:

• A. Reflection
• B. Refraction
• C. Polarization
• D. Diffraction✓
• E. Absorption

Explanation: Option A is ❌ Reflection means the return of light or sound waves from a surface.Option B is ❌ Refraction means Refraction is the bending of light (it also happens with sound, water and other waves) as it passes from one transparent substance into another.Option C is ❌ Polarization means the figure that the instantaneous electric field traces out with time at a fixed observation point that is normal to the direction of propagation.Option D is ✅ Diffraction means the spreading of waves around obstacles.Option E is ❌ Absorption means refers to the reception of energy.

Q28. An object with constant mass rests on a horizontal surface whose coefficient of friction is 0.2. If a horizontal force F is applied to the object, what will be the effect(s) on the object? I. It may move with constant speed in the direction of F once it has been set in motion.II. It may remain at rest.III. It may accelerate.IV. It may move with constant speed in an opposite direction

• A. I, II and III only✓
• B. I and III only
• C. II and IV only
• D. IV only
• E. III only

Explanation: 1. It is possible that object starts to accelerate when the frictional force becomes greater enough due to objects motion to equalize the forward force, so the object starts moving at a constant speed.2. Now, if the force is less than product of coefficients of friction and weight of the object may remain at rest.3. If the force applied is greater than product of coefficient of friction and weight of the object, the object accelerates on the direction of force.

Q29. What is the relationship between the atomic number ‘Z’ and the mass number ‘A’ and the number of neutrons ‘N’ in a nucleus?

• A. Z=AN
• B. Z=A/N
• C. Z=N/A
• D. Z=A-N✓
• E. Z=N.A

Explanation: The difference between the mass number ’A’ and the atomic number Z gives the numberof neutrons (N) in a given nucleus: N = A − Z.So the correct option is D

Q30. A constant force acting on a body of mass 5kg, changes its speed from 2 m/s to 7 m/s in 10 seconds. The direction of motion of the body remains unchanged. Find the magnitude of the force?

• A. 1.5N
• B. 2.5N✓
• C. 3.5N
• D. 4.5N
• E. 6.5N

Explanation: The correct option is B

Q31. Find the maximum speed at which a car can turn around a curve of 30 m radius on a level road if the coefficient of friction between their tyres and the road is 0.4.

• A. 9.84 m/s
• B. 10.84 m/s✓
• C. 11.84 m/s
• D. 12.84 m/s
• E. 8.84 m/s

Explanation: The correct option is B

Q32. The scalar product of two vectors A and B can be written as:

• A. A.B = AB sinø
• B. A.B = AB tanø
• C. A.B = AB sin2ø
• D. A.B = AB cosø✓
• E. A.B = AB tan2ø

Explanation: The scalar product (or dot product) of two vectors A and B is given by A.B = AB cosø, where ø is the angle between the vectors. This is because the scalar product measures the extent to which two vectors point in the same direction. Option D is correct because it reflects this definition. Option A, C, and E are incorrect as they involve the sine or tangent functions, which pertain to the vector product or other contexts, not the scalar product. Option B incorrectly uses the tangent function, which is irrelevant here.

Q33. One thousand watts of electric power are transmitted to a device by means of two wires,each of which has resistance of 2 Ω. If the resulting potential difference across the device is 100 volts, the potential difference across the source supplying the power is:

• A. 20V
• B. 40V
• C. 100V
• D. 140V✓
• E. 500V

Explanation: The correct option is D

Q34. The intensity of an electric field at a particular point is greater if an electric charge experience _ force at that point

• A. A smaller
• B. A greater✓
• C. No
• D. First Smaller and then Greater
• E. First Greater and then Smaller

Explanation: As the electric field intensity is force/charge so there is a direct relation between the force and electric field intensity so as the force increases electric field intensity also increases.Greater the force greater will be the electric field intensity.So option B is correct

Q35. ½ Horsepower equals to:

• A. 746 Watts
• B. 726 Watts
• C. 373 Watts✓
• D. 326 Watts
• E. 313 Watts

Explanation: The correct option is C

Q36. A 60 watt bulb is operated by 240 Volts. What is the current through the bulb?

• A. 3.25 A
• B. 2.75 A
• C. 1.75 A
• D. 0.25 A✓
• E. 4.95 A

Explanation: The correct option is D

Q37. A body of mass 5 kg, initially at rest, is moved by a horizontal force of 2 N on a smooth horizontal surface. Find the work done by the force in 10s?

• A. 10J
• B. 20J
• C. 30J
• D. 40J✓
• E. 25J

Explanation: The correct option is D

Q38. Which of the following factors has no effect on boiling point?

• A. Pressure
• B. Intermolecular Force
• C. Amount of Liquid✓
• D. Impurities in the Liquid
• E. None of the options given

Explanation: The boiling point of a liquid is the temperature at which it turns to vapor. Liquids turn to vapor when their vapor pressure equals the pressure of the surrounding air.As elevation increases, pressure decreases, and water can boil at a lower temperature.If strong intermolecular forces exist between the molecules then the boiling point increases. An effective way of raising the boiling point of a liquid is to add another ingredient. When a solute is dissolved into a solvent, a solution is created. A solution usually boils at a higher point than the pure solvent.The boiling point of a substance is not directly affected by the amount or quantity of the liquid. It remains constant as long as the pressure remains constant. The factors that do affect boiling point include pressure, intermolecular forces, and impurities.

Q39. Yeast can be used to convert simple sugar to:

• A. Ethanoic Acid and Oxygen
• B. Ethanol and CO2✓
• C. Ethanol and Oxygen
• D. Starch and CO2
• E. Starch and Oxygen

Explanation: Yeast does the process of fermentation and to be more specific it does Alcoholic fermentation with the help of an enzyme called as Zymase which converts simple sugar to ethanol and also releases the CO2 gas which is then further used in brewing industry and bakery goods, so the correct option is B

Q40. The maximum yield of ammonia can be obtained at 200 ̊C and pressure of ?

• A. 125 atmospheres
• B. 200 atmospheres
• C. 250 atmospheres
• D. 500 atmospheres
• E. 1000 atmospheres✓

Explanation: The necessary conditions for getting maximum yield of ammonia are as follows :(i) High Pressure : When 4 volumes of a mixture of nitrogen and hydrogen are reduced to 2 volumes of ammonia, the pressure drops. In order to have maximum yield the pressure should be very high. The optimum pressure should be between 200 atmospheres to 1000 atmospheres.(ii) Low Temperature : As the reaction is exothermic in nature, so the temperature should be low. It is found for maximum yield, temperature should be between 450° to 500°C (optimum temperature).(iii) Catalyst: Ferric oxide is used as a catalyst.So the correct answer should be E✅.NOTE: a very high pressure is chosen to move the equilibrium position to the right, making more ammonia. However, it is expensive to achieve very high pressures. Stronger equipment is needed, and more energy is needed to compress the gases.

Q41. H3PO4 dissolves in water and ionizes as follows:

• A. H3PO4 = 3H+ + PO43-
• B. H3PO4 = 4H+ + PO43-
• C. H3PO4 = 5H+ + PO43-
• D. H3PO4 = H+ + H2PO4-✓
• E. H3PO4 = H3O+ + PO43-

Explanation: This represents the first step of the ionization of phosphoric acid in water, which is correct. H3PO4 dissociates into H+ and H2PO4-.

Q42. What happens when a copper atom becomes a copper ion?

• A. It oxidizes by losing one electron.
• B. It oxidizes by losing two electrons.✓
• C. It oxidizes by gaining two electrons.
• D. It reduces by losing two electrons.
• E. It reduces by gaining two electrons.

Explanation: As in free state Copper has 0 charge, so when it loses its 2 electrons (oxidation) it becomes oxidized and becomes a Copper ion with the oxidation state of 2.So the correct option is B

Q43. Identify the hydrocarbon formed when dibromoethane is boiled with alcoholic KOH:

• A. Methane
• B. Ethane
• C. Propene
• D. Ethyne✓
• E. Ethene

Explanation: Explanation is given below.

Q44. Polyvinyl Chloride is an industrial polymer prepared from:

• A. Ethene
• B. Ethyne
• C. Ethane
• D. Chlorine
• E. None of the given options✓

Explanation: The electrolysis of salt water produces chlorine. The chlorine is then combined with ethylene that has been obtained from oil. The resulting element is ethylene dichloride, which is converted at very high temperatures to vinyl chloride monomer. These monomer molecules are polymerized forming polyvinyl chloride resin.As the PVC is then formed by the polymerization of the ethylene dichloride so no such option is given so the correct answer is option E

Q45. What will be the products from the following reaction?

• A. Ortho dinitrobenzene and water
• B. Para dinitrobenzene and water
• C. Meta dinitrobenzene and water✓
• D. 2, 4, 6 trinitrobenzene
• E. None of the given options

Explanation: So as in this case the NO2 group is a meta directing group due to the presence of the unsaturated bond Meta dinitrobenzene and water will be produced and it is a nitration process.So the correct option is C

Q46. The color of transitions metal complexes, is associated with

• A. Losing electrons
• B. Gaining electrons
• C. d-d transition of electrons✓
• D. Unpaired electron
• E. Paired electron

Explanation: The striking colors exhibited by transition-metal complexes are caused by excitation of an electron from a lower-energy d orbital to a higher-energy d orbital, which is called a d–d transition.

Q47. In “Contact Process” for the preparation of H2SO4, the catalyst used is:

• A. NO + NO2
• B. V2O5✓
• C. Nickel
• D. Palladium
• E. Cobalt

Explanation: The catalyst used in the contact process is vanadium pentoxide. The action of the catalyst is not to yield more product but to make the reaction faster by forcing the reaction to reach equilibrium quickly. So the correct option is B

Q48. "S Block Elements" in the periodic table include only:

• A. Boron Family
• B. Halogens and inert gasses
• C. Alkali and alkaline earth metals✓
• D. Alkali metals
• E. Transition elements

Explanation: "s" block elements are those in which the "s" subshell is the valence shell. i.e.they contain either 1 or 2 electrons in their valence shell. Option A: Boron family(IIIA) members contain 3 electrons in their valence shells. So,they are part of p-block.Hence,this option is incorrect. Option B: Halogens (7A) contain 7 electrons in their valence shells while noble gasses (except helium) contain 8 electrons in their valence shells.So,they are part of p-block elements.So,Option B is incorrect. Option C: Alkali metals contain 1 electron in their valence shell while alkaline earth metals contain 2 electrons in their valence shells. So,they constitute the s-block.So,Option C is correct. S block comprises of 14 elements: hydrogen (H), lithium (Li), helium (He), sodium (Na), beryllium (Be), potassium (K), magnesium (Mg), rubidium (Rb), calcium (Ca), cesium (Cs),strontium (Sr), francium (Fr), barium (Ba), and radium (Ra). Option D: Alkali metals are a part of s-block but s-block does not ONLY contain alkali metals.It also contains alkaline earth metals.So,Option D is incorrect. Option E: Transition elements are those elements in which only d-subshell is in the process of filling.Hence,they are a part of d-block.So,Option E is incorrect.

Q49. Which one of the following is radioactive Hydrogen?

• A. Protium
• B. Tritium✓
• C. Hydrogen Molecule
• D. Deuterium
• E. None of the given options

Explanation: Tritium or hydrogen-3 (H) is a rare and radioactive isotope of hydrogen. In general,isotopes with the highest neutron to proton ratio are radioactive. Option A: Protium is stable and non-radioactive because it consists of only 1 proton and 1 electron.Thus,Option A is incorrect. Option B: Tritium (3H) is the only radioactive isotope of hydrogen. The nucleus of a tritium atom consists of a proton and two neutrons. This contrasts with the nucleus of an ordinary hydrogen atom (which consists solely of a proton) and a deuterium atom (which consists of one proton and one neutron). Option C: Hydrogen molecules are very stable and can exist independently in nature. Molecules ,in general, are very rarely radioactive in nature.So,Option C is incorrect. Option D: Deuterium has one electron,one proton and one neutron which makes them stable and non-radioactive. Option E: Since we have already found the answer,this option is incorrect.

Q50. A Buffer Solution is used to:

• A. Change the pH drastically
• B. Resist changes in pH✓
• C. Act as a strong acid
• D. Act as a strong base
• E. Add color to the solution

Explanation: A buffer contains a weak acid and its conjugate base (or vice versa). It neutralizes added acids or bases, maintaining nearly constant pH. Thus, its main role is to resist pH changes

Q51. The oxidation number of all the elements in the free state is:

• A. Negative
• B. Positive
• C. Zero✓
• D. Impossible to determine

Explanation: The oxidation state of a free element is zero. For a simple (monoatomic) ion, the oxidation state is equal to the net charge on the ion. Option A: Oxidation state is negative when an element or molecule gains an electron. So,Option A is incorrect. Option B: Oxidation state is positive when an element or molecule loses an electron. So,Option B is incorrect. Option C: Oxidation state of free elements and neutral molecules is considered zero. So,Option C is correct. Option D: Oxidation state of free elements is considered zero and hence,can be determined.So,Option D is incorrect.

Q52. The reaction H₂ + I₂ —> 2 HI is independent of:

• A. Temperature
• B. Concentration
• C. Catalyst
• D. Pressure✓
• E. Reactants

Explanation: If the moles of reactants and products are equal,then change in pressure does not affect the reaction. Option A: Since the reaction is exothermic,an increase in temperature will move the reaction towards the reactant side. So,temperature does affect this reaction. Option B: Increasing concentration of reactants or products will move the reaction in forward or reverse direction respectively. So,this reaction is not independent of concentrations. Option C: A catalyst is a substance that can be added to a reaction to increase the reaction rate without getting consumed in the process. The addition of a catalyst to a reaction will affect the reaction. Option D: Pressure does not affect the rate of reaction when moles of reactants and products are equal to each other. If the number of moles of reactants are greater than the number of moles of products,then increasing pressure will move the reaction towards the product side. On the other hand,if the number of moles of products are greater than the number of moles of reactants,then increasing pressure will move the reaction towards the reactant side. So,Option D is correct. Option E: If we add reactants to the reaction,then the reaction tends to move towards the product side,affecting the reaction. Hence,Option E is incorrect.

Q53. Bond Energy of a molecule depends upon:

• A. Bond distance and bond polarity✓
• B. Ionization Energy
• C. Internal Energy
• D. Lattice Energy
• E. Kinetic Energy

Explanation: Bond energy (E) is defined as the amount of energy required to break apart a mole ofmolecules into its component atoms. It is a measure of the strength of a chemical bond.Option A: Bond energy depends on bond distance and bond polarity.Smaller the bond distance between two atoms,stronger will be the bond and higher will be the bond energy.As the bond polarity increases,the attraction between molecules increases which results in an increase in bond energy.That is why,polar bonds are stronger than non polar bonds.Hence,Option A is correct.Option B: Ionization energy is the amount of energy released when an electron is added to the outermost valence shell of an isolated gaseous atom.Ionization energy is related to individual atoms,not bonds between atoms.So,Option B is incorrect.Option C: Internal energy of a system or a body is the total of the kinetic energy due to the motion of molecules and the potential energy of atoms within molecules.E(internal) = E(thermal) + E(bond)Excluding atomic and nuclear energies, the bond energy is often referred to as the “chemical energy”.Internal energy is the sum of thermal energy and bond energy.So,Option C is incorrect.Option D: Bond energy is the amount of energy required to break one mole of bonds of a particular type between two atoms in gaseous state.While, lattice energy is the amount of energy required to completely separate one mole of a solid crystalline ionic compound into its constituent gaseous ions. If you have noticed, bond energy is related to gaseousmolecules while lattice energy is related to solid crystalline compounds.Hence,Option D is incorrect.Option E: Kinetic energy is the energy a body possesses when in motion.Kinetic energy and internal energy have no relation in general.Hence, Option E is incorrect.

Q54. The hybridization between C≡C atoms in C₂H₂ (ethyne) is:

• A. Sp³-Sp³
• B. Sp²-Sp
• C. Sp-Sp✓
• D. Sp²-Sp²
• E. Sp²-S

Explanation: A triple bond is formed when three sp orbitals of one atom overlaps three sp orbitals of another atom. For each carbon, the 2s orbital hybridizes with one of the 2p orbitals to form two sp hybridized orbitals. The sp hybrid orbitals are at 180° to one another.Option A: An sp³-sp³ overlap results in the formation of a single bond which is also its indication.Single bonds exist in ethane.So,Option A is incorrect.Option B: When a sp hybridized carbon forms a single bond with a sp² hybridized carbon,sp-sp² bond is formed.In this case,only a single bond is formed.Option C: An sp-sp overlap results in the formation of a triple bond.E.g.In case of ethyne,sp-sp orbitals of 2 carbon atoms overlap with each other.Also,two unhybridized p-orbitals from each carbon atom overlap with the p-orbitals of other carbon atom forming a triple bond.Hence,Option C is correct.Option D: An sp²-sp² overlap results in the formation of a double bond between two carbon atoms.A double bond exists between two carbon atoms in case of ethene.Hence,Option D is incorrect.Option E: sp²-s overlapping results in the formation of a single bond as is the case of C-H bonds.

Q55. The violet region of visible spectra has the shortest wavelength of about:

• A. 7000 Å
• B. 1000 Å
• C. 4000 Å✓
• D. 2000 Å
• E. 8000 Å

Explanation: The red region extends roughly from 620 to 750 nanometer,the orange region from 590 to 620 nm, the yellow region from 570 to 590 nm, green region from 495 to 570 nm, blue region from 450 to 495 nm and violet region from 380 to 450 nm.This MCQ is based solely on cramming.

Q56. The stable electronic configuration of Cu-29 is:

• A. [Ar] 4s¹ 3d¹⁰✓
• B. [Ar] 4s² 3d⁹
• C. [Ar] 4s⁰ 3d¹⁰
• D. [Ar] 4s² 3d⁸
• E. [Ar] 4s¹ 3d⁸

Explanation: The expected electron configuration for Copper will be 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁹.But,Copper shows the electronic configuration of 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d¹⁰.It is because of the stability associated with a completely filled d-subshell.Same behavior is shown by chromium which shows electronic configuration [Ar] 4s¹ 3d⁵ to half fill d-subshell.Option A is correct because one electron is removed from the s-subshell and is added to the d-subshell.Option B is incorrect.Option B represents the expected electronic configuration of copper.However,copper shows electronic configuration of 4s¹ 3d⁹, a little different from our expectations.Option C is incorrect because the total electrons in this case will be 28,not 29.Option D is incorrect because the total electrons in this case will be 28,not 29.It is the electronic configuration of nickel(Ni).Option E is incorrect as it represents the electronic configuration of cobalt(Co),not copper.

Q57. At standard temperature and pressure (STP), 0.5 moles of a gas occupy a volume of:

• A. 22.4 dm³
• B. 89.6 dm³
• C. 11.2 dm³✓
• D. 44.8 dm³
• E. 51.4 dm³

Explanation: One mole of all ideal gasses at standard pressure and temperature occupies a volume of 22.414 dm³.So,volume of half moles should be smaller than 22.4 dm³.As, 1 mole of an ideal gas = 22.4 dm³Divide both sides by 2: ½ moles of an ideal gas = 22.4/2 dm³ 0.5 moles of an ideal gas = 11.2 dm³ Hence, correct answer is 11.2 dm³.Option A is incorrect because it represents the volume of 1 mole of an ideal gas,not 0.5 moles.Option B is incorrect because it represents the volume of 4 moles of an ideal gas.Option C is correct because it describes the volume of half moles of an ideal gas(half of 22.4 dm³).Option D is incorrect because it describes the volume of 2 moles of an ideal gas.Option E is incorrect because it is greater than 22.4 dm³ and represents volume of 2.3 moles of an ideal gas.

Q58. If the absolute temperature of a gas is doubled and the pressure is reduced to one half the volume of the gas will be:

• A. Remains unchanged
• B. Increase four times✓
• C. Reduce to ¼
• D. Be double
• E. Decrease four times

Explanation: According to Boyle' law,Volume is inversely proportional to the pressure.So,if pressure is reduced to one half,volume will become double.According to Charles' law,Volume is directly proportional to temperature.So,if temperature is doubled,volume is also doubled.Another way to understand this question is by using ideal gas law:The ideal gas law formula is PV=nRT. As, V=nRT/P—--->(1)Now, V*=nR2T÷ P/2OR V*=4 nRT÷ PFrom equation (1): V*=4 VHence,volume increases four times.So, Option B is correct.

Q59. Which one of the following is a step in the reaction between methane and chlorine?

• A. Cl₂ —> 2Cl•
• B. CH₃• + Cl₂ —> CH₃Cl + Cl•
• C. CH₃• + HCl —> CH₄ + Cl•
• D. CH₃Cl + Cl₂ —> CH₂Cl₂ + HCl✓
• E. CH₂Cl• + HCl —> CH₃Cl + Cl•

Explanation: The reaction between chlorine and methane takes place as follows:Reaction 1: CH4 + Cl₂—>CH3CI + HCIReaction 2: CH3CI + Cl₂—>CH₂Cl₂ + HCIReaction 3: CH₂Cl₂ + Cl₂—->CHCl3 + HCIReaction 4: CHCl3 + Cl2—->CCl4 + HClReaction 2 is given in D option,so Option D is the right answer.

Q60. Positively charged Oxygen when bonded with three other atoms or group of atoms is called:

• A. Oxygen ion
• B. Oxonium ion✓
• C. Oxide ion
• D. Hydroxide ion
• E. Carbonyl ion

Explanation: If positively charged oxygen bonds with 3 other atoms or groups of atoms,then it is called oxonium ion.E.g. Hydronium ion (H3O+). Option A: When an oxygen atom loses an electron,it becomes oxygen ion represented as O2-Option B is the correct option as positively charged Oxygen when bonded with three other atoms or groups of atoms is called oxonium ion.Option C: O2– ion with oxygen in the oxidation state of −2 is called oxide ion.It is another term for oxygen ion.Option D: Hydroxide ion means OH-Hydroxide ions are formed as a result of splitting of water molecules.Option E: In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O.Carbonyl ion does not exist.

Q61. Which orbital has the lowest energy?

• A. 3d
• B. 4s
• C. 3p✓
• D. 4f
• E. 5f

Explanation: To solve this question,use the n+l rule.Greater the value of n+l,greater will be the energy.Here, n=principal quantum number l=azimuthal quantum numberOption A: n+l value of 3d will be 5(3+2)Option B: n+l value of 4s will be 4(4+0)Option C: n+l value of 3p will be 4(3+1)Option D: n+l value of 4f will be 7(4+3)Option E: n+l value of 5f will be 8(5+3)As we can see that n+l values of Option B and C are the same.If two subshells or orbitals have the same n+l value, the subshell or orbital with lower n value will have lower energy.

Q62. Molecular orbital picture of O2 indicates:

• A. One unpaired electron
• B. Two unpaired electrons✓
• C. Three unpaired electrons
• D. One paired electron
• E. None of the given options

Explanation: Oxygen molecule has two bonds. i.e., one sigma bond and one pi bond. The last two electrons in 2px and 2py orbitals will remain unpaired. Thus,Oxygen molecule has 2 unpaired electrons.Therefore, oxygen molecule has paramagnetic character due to the presence of two unpaired electrons.

Q63. If the pH of a solution is 7.00 it represents:

• A. Acidic Solution
• B. Basic Solution
• C. Neutral Solution✓
• D. Molar Solution
• E. None of the given options

Explanation: pH scale ranges from 0-14 with 0 being strongly acidic and 14 being strongly basic.As the pH increases acidity decreases and basicity increases.7 on the pH scale is considered neutral.Option A: Any solution with pH less than 7 is considered acidic with 0 being most acidic and 6 being slightly acidicOption B: Any solution with pH greater than 7 is considered basic with 14 being most basic and 8 being slightly basic.Option C: A neutral solution is given a pH of 7.Hence,on a pH scale,7 is the point of neutrality.Option D: A molar solution is a solution in which 1 mole of a compound is dissolved in a total volume of 1 liter. For example: The molecular weight of sodium chloride (NaCl) is 58.44, so one gram molecular weight (= 1 mole) is 58.44g.It is not related to pH.Option E: Since we have already found the answer,this option is not applicable.

Q64. Rate determining step in SN1 type reaction is always the:

• A. Fast Step
• B. Slow Step✓
• C. Intermediate Step
• D. Second Step
• E. None of the given options

Explanation: Rate determining step is the slowest step within a chemical reaction. The slowest step determines the rate of chemical reaction.Option A: As the rate determining step is the slowest step of a mechanism,a fast step cannot be a rate determining step.Option B: In an SN1 reaction, the rate determining step is the loss of the leaving group to form the intermediate carbocation. The more stable the carbocation is, the easier it is to form, and the faster the SN1 reaction will be.The loss of leaving group is the slow and first step of SN1 reactions.Option C: SN1 reactions contain only 2 steps.It does not contain any intermediate step,so this option is incorrect.Option D: Second step in SN1 reactions is a faster step than the first step.So,it can not be the rate determining step.Option E: Since,we have already found our answer,this option is not valid.

Q65. Acetic acid is a weak acid because in aqueous solution it ionizes:

• A. Partially
• B. Completely
• C. Easily
• D. With difficulty✓
• E. None of the given options

Explanation: Weak acids are acids that don't completely dissociate in solution. The strength of a weak acid depends on how much it dissociates: the more it dissociates, the stronger the acid.The strength of an acid depends upon the extent of ionization. Acetic acid is highly soluble in water but it dissociates partially in the aqueous solution to produce a small amount of H+ ions and therefore. considered as a weak acid.Option A: Acetic acid ionizes to a very little extent in water,so partially soluble is not the right answer.Option B: An acid which is completely ionized in its aqueous solution is considered a strong acid.Since,acetic acid is a weak acid,it can not ionize completely in water.Option C: Acetic acid is a weak acid and hence,can not ionize easily in a solution.Option D: Since acetic acid is not a strong enough proton donor to be entirely converted to hydronium ions in aqueous solution, it is called a weak acid.Hence,acetic acid is considered a weak acid because of its difficult ionization Option E: Since we have already found our option,this option is not valid.

Q66. Which of the following is a covalent hydride?

• A. NaBH₂
• B. ZnH₂
• C. NaH
• D. CaH₂
• E. H₂S✓

Explanation: Hydrides are classified based on the element – hydrogen bonding. For example, if hydrogen is bonded to a metal, metallic hydrides are formed. If hydrogen is bonded to non-metal, covalent hydrides are formed, and if hydrogen forms bonds with s-block elements, ionic hydrides are formed.Option A: Hydrides are binary compounds (contain only 2 elements).So,NaBH2 can not be considered a hydride.Option B: Since Zinc(Zn) is a metal,it forms an intermediate hydride with hydrogen.Option C: Since sodium(Na) is a metal,it forms an ionic hydride with hydrogen.Option D: Since calcium(Ca) is a metal,it forms an ionic hydride with hydrogen.Option E: Since sulphur(S) is a non-metal,it forms a covalent hydride with hydrogen.Hence,Option E is the right option.

Q67. Which of the following hydrocarbons has the lowest normal boiling point?

• A. Ethane✓
• B. Propane
• C. Butane
• D. Pentane
• E. Hexane

Explanation: As the number of carbon atoms in alkane increases,melting and boiling point also increases.The reason is that as the carbon chain gets longer, there are more electrons in a molecule. This means that there are more (relatively) stronger intermolecular forces between the molecules. As a result, it takes more energy to break these forces, and thus the melting or boiling points increase.Option A: Since ethane has the lowest number of carbon atoms(2) ,so its boiling point will be lowest.Option B: Propane has 3 carbon atoms and second lowest boiling point among the options.Option C: Butane has 4 carbon atoms and third lowest boiling point among the options.Option D: Pentane has 5 carbon atoms and the fourth lowest boiling point among the options.Option E: Hexane has 6 carbon atoms and highest boiling point among the options.

Q68. The fruit develops from the:

• A. Style
• B. Stigma
• C. Ovary✓
• D. Ovule
• E. Pistil

Explanation: Option A:Style is the name for the stalk of the pistil. When pollen reaches the stigma, it begins to grow a tube through the style called a pollen tube, which will eventually reach the ovary. Option B: Stigma is the female part of the flower. It is the sticky bulb that you see in the center of flowers and is the part where the pollen lands and starts the fertilization process.Option C:The ovary often supports a long style, topped by a stigma.After fertilization,ovary develops into fruit.Option D:The ovule is the organ that forms the seeds of flowering plants. It is borne in the ovary of the flower and contains nucellus.Option E: Pistil, the female reproductive part of a flower. The pistil, centrally located, typically consists of a swollen base, the ovary, which contains the potential seeds, or ovules; a stalk, or style, arising from the ovary; and a pollen-receptive tip, the stigma, variously shaped and often sticky.

Q69. During pollination, pollen is transferred from:

• A. Anther to Ovary
• B. Anther to Stigma✓
• C. Anther to Filament
• D. Filament to Anther
• E. Filament to Stigma

Explanation: Option A is incorrect because pollen is transferred from male to female part of a flower.Not from anther to male reproductive part.Option B: Pollens from anther reaches stigma by a process called pollination.The pollen grain germinates to form a pollen tube that grows through the carpel's style and transports male nuclei to the ovule to fertilize the egg cell and central cell within the female gametophyte in a process termed double fertilization.Hence,Option B is correct.Option C is incorrect because pollen is transferred from male to female part of a flower.Option C describes the transfer of pollen from anther to filament which is incorrect.Option D is incorrect because pollen is transferred from male to female part of a flower.Option D describes the transfer of pollen from filament to anther which is incorrect.Option E: During pollination,pollen formed in anther is transferred to stigma.Option E describes the transfer of pollen from filament to stigma which is incorrect because pollen is not made in filament.Pollens are made in anther.

Q70. The formation of haploid cells through meiosis takes place in structures numbered which of the following;

• A. 1 & 5
• B. 1 & 6
• C. 3 & 4✓
• D. 1 , 4 & 8
• E. 4 , 7 & 9

Explanation: Meiosis takes place in ovules and anther to produce haploid gametes.These haploid gametes then combine to form diploid zygote.Option A is incorrect because 5 refers to filament where meiosis does not take place.So,Option A is incorrect.Option B is incorrect because 6 refers to petals which function to attract insects for pollination.Petals are not a part of the reproductive system.Option C: 5 and 6 refers to anther and pollen sacs.Meiosis takes place in these areas to produce haploid gametes.So,Option C is correct.Option D is incorrect because 8 refers to stalk which is not a reproductive part of a plant.So,Option D is incorrect.Option E is incorrect because 9 refers to stigma which functions to capture pollen. Stigma is sticky to capture pollens.It does not produce gametes by meiosis.So,Option E is incorrect.

Q71. Example of cnidarians includes all except:

• A. Corals
• B. Jellyfish
• C. Hydra
• D. Sponges✓
• E. Sea anemone

Explanation: Cnidarians are invertebrates belonging to the phylum Cnidaria. All cnidarians are aquaticand most of them live in the ocean.Sponges are a primitive sedentary aquatic invertebrates with a soft porous body that are typically supported by a framework of fibres or calcareous or glassy spicules.This MCQ is based on examples given in chapter 10 of Biology.Do remember all the examples of chapter 10 to obtain maximum marks

Q72. Which of the following negates Lamarck's Theory?

• A. Elongated forelimbs and neck of giraffe
• B. Custom of circumcision✓
• C. Evolution of snake
• D. Foot of modern horse
• E. Webbed feet of duck

Explanation: Lamarck introduced "Inheritance of Acquired Characteristics". Lamarck believed that traits changed or acquired over an individual's lifetime could be passed down to its offspring. For example: Giraffes obtained long necks as a result of a long series of generations stretching their necks to obtain the leaves present on tall trees.This does not hold true for the surgery involving circumcision.This type of inheritance, sometimes called Lamarckian inheritance, is now known to be untrue.

Q73. How many bones are present in the wrist?

• A. Four bones
• B. Six bones
• C. Eight bones✓
• D. Ten bones
• E. Many bones

Explanation: Your wrist is made up of eight small bones called carpal bones, while your forearm contains two long bones: radius and ulna.

Q74. The stomata pore will open when the:

• A. Turgor of the guard cells decreases
• B. Turgor of the guard cells increases✓
• C. Leaf is kept in the dark
• D. Amount of CO₂ in the guard cells increases
• E. Atmosphere becomes heavy with water vapor

Explanation: Stomata control the flow of gasses in and out of leaves.Stomata are composed of two guard cells. These cells have walls that are thicker on theinner side than on the outer side. This unequal thickening of the paired guard cells causes the stomata to open when they take up water and close when they lose water.Stomata opens during the day and closes during the night.Option A: When the guard cells lose water,turgor pressure decreases and stomata closes.So,Option A is incorrect.Option B: When the guard cells gain water,turgor pressure increases and stomata opens.So,Option B is correct.Option C: When stomata is kept in dark or during the night,stomata remains closed as no photosynthesis takes place during night.Option D: Higher than ambient CO2 concentrations mediate a closure of stomatal pores in plants and conversely, low CO2 concentrations trigger opening of stomatal pores.Option E: Stomata does not open as a result of direct response to humidity. Stomata pores open when there is a loss of water from the leaf.

Q75. The part of an enzyme where a substrate binds is called the:

• A. Allosteric site
• B. Activation site
• C. Catalytic site
• D. Active site✓

Explanation: The active site is the specific region where the substrate fits and reaction occurs.

Q76. In cockroaches, the portion from pre-oral cavity to gizzard is known as:

• A. Proctodaeum
• B. Mesenteron✓
• C. Stomodeum
• D. Maxillae
• E. Mandibles

Explanation: The alimentary canal is a tube, usually coiled, which extends from the mouth to the anus, and consists of three regions: the foregut, midgut, and hindgut. The foregut is also known as the stomodaeum; the midgut is also known as the mesenteron; and the hindgut is also known as the proctodaeum.The portion from pre-oral cavity to gizzard is called mesenteron.Option A: Proctodaeum is also called hindgut.It consists of ileum, colon and rectum. They help in the absorption of water and saltsOption B: Midgut or mesenteron: It is the middle part of the alimentary canal. Gastric or hepatic caeca secrete digestive juices that are present at the junction of foregut and midgut.Option C: Stomodeum is also called foregut. The foregut opens into a gap, where undigested food is temporarily stored.Option D:Maxillae (singular Maxilla) are part of an insect's mouthparts. Maxillae usually end in a sharp point and so the maxillae act like pincers. They are used to hold and manipulate food so that it can be chewed or sliced by the mandibles.Option E: The function of mandibles is to grasp, crush, or cut the food. Also, mandibles provide defense against predators as they are hard due to chitin composition.

Q77. If a ribose molecule was bonded to one adenine molecules and one phosphate molecules, would have a:

• A. Ribonucleotide✓
• B. Nucleotide
• C. Nucleic Acid
• D. ATP
• E. ADP

Explanation: Option A: The general structure of a ribonucleotide consists of a phosphate group, a ribose sugar group and a nitrogen containing base.Nucleobase can be one of the following:AdenineCytosineUracil (Thymine in case of DNA)GuanineSo,Option A is correct.Option B: A nucleotide is the basic building block of nucleic acids(Both RNA and DNA).Nucleotide is incorrect because the question specifies a ribose molecule.So,Option is more preferable. Option C: A complex organic substance present in living cells, especially DNA or RNA, whose molecules consist of many nucleotides linked in a long chain.Nucleic acids carry genetic information which is read in cells to make the RNA and proteins by which living things function.Option D: Adenosine triphosphate, also known as ATP, is a molecule that carries energy within cells. It is the main energy currency of the cell. The structure of ATP is a nucleoside triphosphate, consisting of a nitrogenous base (adenine), a ribose sugar, and three serially bonded phosphate groups.Option E: Adenosine diphosphate (ADP) is a nucleoside phosphate composed of a ribonucleoside and two phosphate groups. It means it has a ribose as its sugar and two phosphate groups attached. Its nucleoside contains a purine base, i.e. an adenine attached to the ribose sugar. ADP is essential in photosynthesis and glycolysis. It is the end-product when adenosine triphosphate ATP loses one of its phosphate groups. The energy released in the process is used to power up many vital cellular processes.

Q78. _pairs of cranial nerves and _pairs of spinal nerves constitute the peripheral nervous system in humans

• A. 6...12
• B. 12...24
• C. 24...12
• D. 31...12
• E. 12...31✓

Explanation: Nerves emerging from the brain are called cranial nerves. Nerves emerging from the spinal cord are called spinal nerves. The cranial nerves are a set of 12 paired nerves that arise directly from the brain. They can be sensory, motor, or mixed. On the other hand, there are 31 pairs of spinal cords. They are all mixed nerves.

Q79. Which of the following are not pairs of spinal nerves?

• A. Cervical
• B. Thoracic
• C. Lumbar
• D. Sacral
• E. Coccygeal✓

Explanation: In total, there are 31 pairs of spinal nerves grouped regionally by spinal region. More specifically, there are eight cervical nerve pairs (C1-C8), twelve thoracic nerve pairs (T1-T12), five lumbar nerve pairs (L1-L5), 5 sacral (S1-S5), and a single coccygeal nerve pair.

Q80. Identify the correct statement:

• A. Protractor and retractor muscles move the arm away from the body and towards the body.
• B. Abductor and adductor muscles move the arm in forward and backward directions.
• C. When the biceps contract, the elbow opens straight.
• D. When triceps contract, the elbow bends.
• E. None of the given options.✓

Explanation: Option A: The ability to protrude (extend) or evert (turn inside out) an organ generally requires protractor and retractor muscles.So,this Option is incorrect.Option B: Abductor muscles are responsible for moving the leg away from the body's midline, while the adductors are responsible for moving the leg back towards the body's midline.Hence,Option B is incorrect.Option C: The biceps and triceps act against one another to bend and straighten the elbow joint. To bend the elbow, the biceps contract and the triceps relax.So,when biceps contract, elbow bends.So,option C is incorrectOption D: To straighten the elbow, the triceps contract, and the biceps relax. When the triceps contract, the elbow opens straight rather than bending. Therefore,Option D is incorrect.The ability to protrude (extend) or evert (turn inside out) an organ generally requiresprotractor and retractor muscles.Option E: Since all of the above-given options are incorrect, hence this option is correct.

Q81. The function of an enzyme is to:

• A. Cause chemical reactions that would not otherwise take place
• B. Change the rate of a chemical reaction✓
• C. Change the direction of a chemical reaction
• D. Raise the activation energy of a chemical reaction
• E. None of the given reactions

Explanation: Option A: Enzymes can not initiate a chemical reaction.They can only accelerate a chemical reaction.So,option A is incorrect.Option B: Enzymes accelerate a chemical reaction by reducing the activation energy of a specific chemical reaction.So,Option B is correct.Option C: Enzymes can not change the direction of a given reaction.They can only speed up an already started reaction.So,Option C is incorrect.Option D: Enzymes do not raise the activation energy.Enzymes actually decrease the activation energy to lower the energy required for the process.So, Option D is incorrect.Option E: We have already found the correct answer, so this option is incorrect.

Q82. The scientific name of the dog is canis familiaris and that of the coyote is canis latas.This indicates that both the dog and the coyote are members of the :

• A. Same genus but different species✓
• B. Same species but different genera
• C. Same genus but different classes
• D. Same species but different classes
• E. Same class but different genera

Explanation: The process of naming living organisms is called "BINOMIAL NOMENCLATURE".Im this process,an organism is given a name consisting of two words;First word represents GENUS and second word represents SPECIES.For example; Homo sapiens is the scientific name for humans.Here, homo is the genus and sapiens is the specie.Since,in the name of dog(Canis familiaris) and coyote(Canis latas),only the first letter is the same.So, they have the same genus but different species.Hence,Option A is incorrect.Option B and D are incorrect because their specie names(second words) are different.Option C is incorrect because they have the same class.Option E is incorrect because they have the same genera.Taxonomic hierarchy is given below:DomainKingdomPhylumClassOrderFamilyGenusSpeciesMnemonic:Dumb King Philip Came Over From Great Spain

Q83. The tube that brings urine from the kidneys to the bladder is the:

• A. Urethra
• B. Ureter✓
• C. Uterus
• D. Eustachian tube
• E. Bile duct

Explanation: Option B is correct.Ureter is the tube that brings urine from kidney to the urinary bladder.So, Option B is correct.Option A: Urethra tube through which urine leaves the body. It empties urine from the bladder.So,Option A is incorrect.Option C: Your uterus is a pear-shaped organ in the female reproductive system. It's where a fertilized egg implants during pregnancy and where the baby develops until birth. It's also responsible for the menstrual cycle in females.So,Option C is incorrect.Option D: The Eustachian tube is a narrow passage leading from the pharynx to the cavity of the middle ear.So,Option D is incorrect.Option E: Bile duct is the duct which transports bile from the liver and the gallbladder to the duodenum.The bile ducts go from the liver to the small intestine, moving bile, where it helps digest the fats in food.So,Option E is incorrect.

Q84. A secretion that digests both carbohydrates and proteins is:

• A. Ptyalin
• B. Saliva
• C. Pepsin
• D. Pancreatic Juice✓
• E. Gastric Juice

Explanation: Option A: Ptyalin is a form of amylase found in the saliva of humans and some other animals. It digests only carbohydrates, not proteins. Hence, Option A is incorrect.Option B: Saliva consists of Water and mucus, Sodium bicarbonate and other salts, and Ptyalin or amylase. Saliva contains the enzyme amylase, also called ptyalin, which is capable of breaking down starch into simpler sugars such as maltose that can be further broken down in the small intestine. But saliva does not contain enzymes for protein digestion. Hence, Option B is incorrect. Option C: Pepsin is an enzyme responsible for protein digestion and is released in the form of pepsinogen in the stomach. Option D: The Pancreas makes pancreatic juices called enzymes. It contains enzymes to break down proteins, carbohydrates and lipids. It contains: Amylase or amylopsin(for starch digestion), Lipase(for lipid digestion), Trypsin in the form of trypsinogen(for protein breakdown). Hence, Option D is correct. Option E: Gastric juice comprises water, mucus, hydrochloric acid, pepsin, and intrinsic factor. Of these five components, pepsin is the principal enzyme involved in protein digestion. There are no enzymes in gastrin for carbohydrate digestion. Hence, Option E is incorrect.

Q85. During inhalation:

• A. The diaphragm flattens out, and the ribs are raised.✓
• B. The diaphragm is raised, and the ribs are lowered.
• C. The diaphragm flattens out, and the ribs are lowered.
• D. The diaphragm is raised, and the ribs are raised.
• E. The diaphragm is raised, and the ribs are stationary.

Explanation: Option A: During the process of inhalation,Diaphragm muscles contract and become less dome-like(flattens out).On the other hand,ribs muscles contract and ribs are elevated giving more space for the lungs.During the process of exhalation,Diaphragm muscles relax and diaphragm becomes more dome-like.Ribs muscles relax and ribs lower down putting pressure on the lungs to expel the airHence,Option A is correct.Options B,D and E are incorrect because diaphragm muscles are not raised during the process of inhalation.Option C is incorrect because during inhalation ribs are elevated, not lowered

Q86. A nerve cell that receives stimuli from the outside is known as a/an:

• A. Sensory neuron✓
• B. Motor neuron
• C. Efferent neuron
• D. Interneuron
• E. Ganglion

Explanation: A sensory neuron is a nerve cell that detects and responds to external signals via receptors and converts this information into electrical impulses. These electrical responses are then transmitted to interneurons via sensory neurons, where information is processed and signals are sent to the effectors through motor neurons.

Q87. The correct order of arrangement, in terms of increasing complexity of the following is: I. OrganII. CellIII. TissueIV. OrganismV. System;

• A. II, I, III, IV, V
• B. II, III, IV, I, V
• C. II, III, I, IV, V
• D. II, III, IV, V, I
• E. II, III, I, V, IV✓

Explanation: The major levels of organization in the body, from the simplest to the most complex are:AtomsMoleculesOrganellesCellsTissuesOrgansOrgan systemsOrganismA mnemonic to remember this: "A Mysterious Cat Talked, Opening Organic Oranges"A- AtomsMysterious - MoleculesCat - CellsTalked - TissuesOpening - OrgansOrganic - Organ SystemsOranges - OrganismHence,Option E is correct.

Q88. When hybrids are crossed, the genotype ratio of the offspring is

• A. 1:1
• B. 3:1
• C. 1:2:1✓
• D. 4:1
• E. 3:2

Explanation: This is known as a monohybrid cross, involving the inheritance of a single trait (e.g., one gene with two alleles). The genotype ratio can be represented as follows:• 1/4 of the offspring are homozygous dominant (e.g., TT).• 1/2 of the offspring are heterozygous (e.g., Tt).• 1/4 of the offspring are homozygous recessive (e.g., tt).This ratio is based on Mendel's law of segregation, which describes how alleles segregate during gamete formation.

Q89. The sperms produced by seminiferous tubules are stored in:

• A. Vas deferens
• B. Urethra
• C. Epididymis✓
• D. Bladder
• E. Sperm duct

Explanation: Sperm production in the testes takes place in coiled structures called seminiferous tubules. Along the top of each testicle is the epididymis. This is a cordlike structure where the sperm mature and are stored.

Q90. Most are saprophytes that obtain their food directly from dead organic matter.

• A. Algae
• B. Fungi✓
• C. Gymnosperms
• D. Angiosperms
• E. None of the given options

Explanation: Option A: Many algae are autotrophs. They contain photosynthetic pigments that help in the autotrophic nutrition. They follow a photo-autotrophic mode of nutrition as they make their own food using the sunlight and other photosynthetic apparatus.Hence, Option A is incorrect.Option B:Most fungi are decomposers.They live on dead animals and plants,secrete digestive enzymes and absorb small molecules obtained by digestion. Saprophytes are organisms that get their nutrition from dead organic matter, including fallen wood, dead leaves or dead animal bodies.Hence,Option B is correct.Option C: Gymnosperms are flowerless plants that produce cones and seeds. Gymnosperm seeds are not encased within an ovary and hence their seeds are exposed.Since gymnosperms belong to kingdom plantae,they are autotrophs and can make their own food.So,Option C is incorrect.Option D: Angiosperms are vascular plants. They have stems, roots, and leaves. Angiosperm seeds are found in a flower.Since angiosperms belong to kingdom plantae,they are autotrophs and can make their own food.So,Option D is incorrect.Option E: We have already found our answer,so this option is incorrect

Q91. Higher altitudes have:

• A. High temperatures
• B. Less rain
• C. High atmospheric pressure
• D. Increased wind velocity✓
• E. All of the given options

Explanation: Option A is incorrect because temperature decreases with increase in altitude. High-altitude locations are usually much colder than areas closer to sea level. This is due to the low air pressure. Air expands as it rises, and the fewer gas molecules —including nitrogen, oxygen, and carbon dioxide—have fewer chances to bump into each other resulting in less generation of heat energy.Option B: In typical convective patterns,(The act or process of conveying; transmission.) common on tropical mountains, Precipitation is usually highest near the cloud base (generally at or below 1,500 m) and decreases significantly at higher elevations. The zone of maximum Precipitation tends to occur at higher elevations in drier climates.Hence,Option B is incorrect.Option C: As altitude increases, the amount of gas molecules in the air decreases—the air becomes less dense than air nearer to sea level. This is regarded as "thin air". Thin air exerts less pressure than air at a lower altitude.Altitude and air pressure are inversely related.Option D: Since obstacles near the ground, such as building structures, plants and etc., disrupt air flow, causing larger frictional force, air flow near the ground is hence slower. On the contrary, there is less friction at higher place which is more exposed. The air flows faster and hence stronger winds.Option E: Since Options A,B and C are incorrect,this Option is also incorrect.

Q92. The nitrates absorbed by the root are converted into:

• A. Animal protein
• B. Ammonia✓
• C. Amino Acids
• D. Carbohydrates
• E. None of the given options

Explanation: Even though nitrogen is the main component of the atmosphere,plants can not use it directly from the atmosphere.Despite abundance of nitrogen in the atmosphere, deficiency of nitrogen is one of the most common reasons for stunted plant growth.Nitrates absorbed by plants by assimilation is converted into ammonia in plants which is then incorporated to make nitrogen - containing organic molecules such as DNA and amino acids

Q93. The contraction of a muscle involves: I. Nerve impulseII. EnergyIII. Calcium ions

• A. I only
• B. II only
• C. I & III only
• D. II & III only
• E. I, II, & III✓

Explanation: Muscle contraction takes place when a NERVE IMPULSE from a motor neuron reaches a neuromuscular junction. The nerve impulse travels to T-tubules, where it causes the sarcoplasmic reticulum to release Ca²+ ions. These ions then attach to troponin, which causes them to move slightly. This movement exposes the binding sites on actin, and myosin attaches to it to contract the muscle. To relax the muscle, ATP provides ENERGY to break the actin-myosin bridge, and the attachment site of actin is covered again. Hence, all three(Nerve impulse, Energy, and Ca²+) are involved in muscle contraction. So, Option E is correct.

Q94. Crop rotation helps in?

• A. Growth of pathogens
• B. Soil infertility
• C. Slowing of crop growth
• D. Eradication of disease✓

Explanation: An easier way to answer this question is to understand that positive impact of crop rotation is being asked.A,B and C are negative outcomes.So, D should be the correct option.Crop rotation helps return nutrients to the soil without synthetic inputs. The practice also works to interrupt pest and disease cycles, improve soil health by increasing biomass from different crops, root structures, and increase biodiversity on the farm.Hence,Option A,B and C are incorrect.Option D:Some pathogens that cause diseases survive in the soil from year to year. Rotating to non-host crops prevents the buildup of large populations of pathogens and hence the eradication of disease.Hence,Option D is correct.

Q95. Advantage of hydroponic farming?

• A. Spreads weeds and soil disease problems
• B. Crops are inhibited to grow in dry parts of the world
• C. Area required for cultivation is reduced✓
• D. None of the given options

Explanation: Hydroponic farming is a beneficial process and is used for scientific research as well as by astronomers to grow vegetables in space.Question is to choose the option which shows advantages of hydroponic farming. Only Option C tells us the advantage of hydroponic farming.All the other options can be characterized as disadvantages of hydroponic farming.Option A: Hydroponic farming does not require pesticide or insecticide.So, it actually prevents disease problems rather than causing them.So,Option A is incorrect.Option B: Hydroponic systems use less water — as much as 10 times less water — than traditional field crop watering methods because water in a hydroponic system is captured and reused, rather than allowed to run off and drain to the environment.Hence,Option B is incorrect.Option C: In a hydroponic system plants are more densely spaced together compared to the size of land that would be needed to grow the same number of plants. Hydroponic farming is a system of growing crops without soil where the plant roots grow in a liquid nutrient solution which is a mixture of essential plant nutrients in the water.Hence,Option C is correct.Option D: Since we have already found our answer,this Option is invalid.

Q96. During a malarial attack the rate of heartbeat and breathing may?

• A. Decrease
• B. Increase✓
• C. Remains constant
• D. No fixed pattern

Explanation: Early symptoms of malaria can include irritability and drowsiness, with poor appetite and trouble sleeping. These symptoms are usually followed by chills, and then a fever with fast breathing.Studies have shown that malaria affects the blood pressure regulatory system causinghypertension(increase in blood pressure), which is a contributor to heart failure. Malaria can also affect vascular pathways that cause inflammation in the heart, which can lead to heart failure.Thus,both breathing and heart rate increases during malarial attack,hence Option B is correct.

Q97. Which plant cells give support to the plant body.?

• A. Sclerenchyma cells✓
• B. Phloem cells
• C. Xylem cells
• D. Parenchyma cells

Explanation: Option A: Sclerenchyma tissue, when mature, is composed of dead cells that have heavily thickened walls containing lignin and a high cellulose content (60%-80%), and serves the function of providing structural support in plants.Hence,Option A is the correct option.Option B: Phloem cells are present in plants and are responsible for the transport of food and organic matter throughout the plant body for storage and use.Hence,Option B is incorrect.Option C: Xylem cells are present in plants and are responsible for the transport of water and minerals from roots to leaves for transpiration and photosynthesis. Hence,Option C is incorrect.Option D: Parenchyma is a type of simple permanent tissue that makes a major part of ground tissues in plants. The unifying characteristic of all parenchyma cells is that they are living at maturity and capable of cell division, giving them important roles in regeneration and wound healing. Other key functions of these cells include photosynthesis, storage, secretion and transport.Hence,Option D is incorrect.

Q98. In plants, which cells carry out photosynthesis?

• A. Sclerenchymatous
• B. Parenchymatous✓
• C. Collenchymatous
• D. None of the above

Explanation: Option A: Sclerenchyma cells, when mature, are composed of dead cells. Sclerenchyma cells have thick, lignified secondary walls and occur throughout all plant tissues. These features make sclerenchyma tissues hard, rigid, and somewhat brittle.They provide support to the plant body and do not perform photosynthesis.Hence,Option A is incorrect.Option B: Parenchyma tissue in plants, typically composed of living cells that are thin-walled, unspecialized in structure, and therefore adaptable, with differentiation, to various functions.Key functions of these cells include photosynthesis, storage, secretion and transport.Thus,Option B is correct.Option C: Collenchyma cells are elongated cells with irregularly thick cell walls. Their thick cell walls are composed of the compounds cellulose and pectin.These cells provide support and structure and do not perform photosynthesis.Hence,Option C is incorrect.Option D: Since we have already found our answer,this option is invalid.

Q99. The police officers _ to the theatre and every nook and corner was completely checked.

• A. Sent to
• B. Were sent✓
• C. Sent
• D. Would have sent to

Explanation: The correct answer is B: 'were sent'. This choice accurately reflects the past tense passive voice. In this sentence, the police officers were the ones receiving the action of being sent, which is typical of a passive construction.Option A lacks the auxiliary verb needed for passive voice.Option C presents an active voice structure without the required auxiliary verb for passive construction.Option D uses the conditional perfect tense, which is inappropriate given the sentence's need for a simple past tense passive construction.

Q100. The teacher asked the students whether they could tell the name of the man who _ steam engine.

• A. Had been invented
• B. Had invented✓
• C. Has been invented
• D. Would be invented

Explanation: B is the correct option because this is active voice and past perfect tense. It correctly indicates that the man performed the action of inventing the steam engine in the past. It fits the context of the sentence, which asks about a historical fact.