Most Repeated MDCAT Physics MCQs

1. 1

   Repeated 10×Circular Motion & Momentum

   An object is moving along a circular path of radius 4m. What will be its angular displacement if it moves 14 m on this circular path?

   • A5.0 radians
   • B3.5 radians✓
   • C4.5 radians
   • D5.5 radians

   Explanation

   Arc length = Radius x Angular displacementS = rθKeeping Arc length as 14m and radius as 4m, we get angular displacement as 3.5 radians.

   Appeared in past papers: 2019

2. 2

   Repeated 9×Circular Motion & Momentum

   If the body is rotating with uniform angular velocity, then its torque is:

   • AZero✓
   • BClockwise
   • CMaximum
   • DRemains the same

   Explanation

   Explanation:If the body is rotating with uniform angular velocity, its angular momentum remains constant, and therefore there is no change in its rotational motion. Since torque is the rate of change of angular momentum, the torque acting on the body is zero. This option is not correct because if there is a clockwise torque acting on the body, it will cause the angular velocity to change, which is not the case when the body is rotating with uniform angular velocity. This option is also incorrect because the maximum torque occurs when the force is perpendicular to the axis of rotation.This opti

   Appeared in past papers: 2009, 2016

3. 3

   Repeated 8×Nuclear Physics

   In relation, which quantity is represented by λ?

   • ADecay constant✓
   • BHalf life
   • CActivity
   • DWavelength

   Explanation

   Explanation is given below.T1/2 represents the 'half-life' with 'T', implying the quantity has something to do with time, and '1/2' representing 'half'.

   Appeared in past papers: 2019

4. 4

   Repeated 8×Work, Power & Energy

   A particle, carrying a charge of 5e, falls through a potential difference of 25 V. What would be energy acquired by the particle in ‘J’.

   • A1.6 x 10-19 J
   • B125 J
   • C125 x 10-19 J
   • D125 x 1.6 x 10-19 J✓

   Explanation

   Electric Potential Energy = Electric Potential x Charge Charge = 5 x 1.6 x 10-19 C Electric Potential Energy = 25V x (5 x 1.6 x 10-19) C This could be manipulated to give us (125 x 1.6 x 10-19) J, which is Option D.

   Appeared in past papers: 2019

5. 5

   Repeated 8×Circular Motion & Momentum

   Which of the following gives the relationship between linear velocity and angular velocity?

   • Av = rω✓
   • Bv = rθ
   • Cv=sω
   • Dv=sθ

   Explanation

   The greater the rotation angle in a given amount of time, the greater the angular velocity. Angular velocity (w) is analogous to linear velocity (v).We can write the relationship between linear velocity and angular velocity in two different ways: v=rw or w=v/r.The difference between these two quantities must also be known;

   Appeared in past papers: 2018

6. 6

   Repeated 8×Alternating Current

   What is the instantaneous power dissipated through a resistor of resistance 10 ohm if it is connected to an AC source of frequency 15 Hz at 1/180 sec if peak value is 20 V?

   • A10 W✓
   • B100 W
   • C40 W
   • DCannot be determined

   Explanation

   UsingVo = V sin(2𝜋ft) = 20 x sin (2𝜋 x 15 x 1/180) = 10 VUsingP = v2/ R = 102 / 10 = 10 W

   Appeared in past papers: 2018

7. 7

   Repeated 8×Atomic Spectra

   What is the number of spectral series in the hydrogen spectrum?

   • AFour
   • BThree
   • CFive✓
   • DOne

   Explanation

   The five spectral series are Lyman, Balmer, Paschen, Brackett and Pfund. In the Lyman series, the electron falls back to n = 1. The spectral lines obtained are in the UV region of the electromagnetic spectrum. In the Balmer series, the electron falls back to n = 2, and the spectral lines obtained are in the visible region of the EM spectrum. Paschen, Brackett, and Pfund spectral lines are obtained in the Infrared region of the EM spectrum.

8. 8

   Repeated 8×Magnetism and Electromagnetic Induction

   Magnetic force on a charged particle is:

   • AQvBl
   • BNone of these
   • CQvB cosθ
   • DQvB sinθ✓

   Explanation

   When a charge moves through a magnetic field, a force is applied on it which is given by:F = QvB sinθQvBl is the motional EMF produced when a conductor moves through a static magnetic field.

9. 9

   Repeated 8×Atomic Spectra

   A set of Atoms in an excited state decays:

   • AIn any general state with lower energy✓
   • BIn any state when excited by electric field
   • CIn any state when excited by magnetic field
   • DNone of these options are correct

   Explanation

   As we know, atoms are stable in the ground state, when they move to another level by gaining energy, they get excited and are ready to lose energy to get back to the ground state. This shows, generally excited state atoms decay to any of the states with lower energy. Hence,the correct option is A in any general state with lower energy which is more stable than the excited state.

10. 10

    Repeated 8×Miscellaneous

    The emission of electrons from a metal surface when exposed to light of suitable frequency is known as:

    • ACompton's effect
    • BPhotoelectric effect✓
    • CCoulomb's law
    • DFaraday's law
    • EOhm's law

    Explanation

    Explanation: photoelectric effect, is a phenomenon in which electrically charged particles are released from or within a material when it absorbs electromagnetic radiation. The effect is often defined as the ejection of electrons from a metal plate when light falls on it.

    Appeared in past papers: 2014, 2015

11. 11

    Repeated 6×Work, Power & Energy

    Which of the following statement shows that no work is done?

    • APushing a car to start it moving
    • BLifting the weights.
    • CThe moon Orbiting the earth.✓
    • DWriting an essay on a page.

    Explanation

    When the moon revolves around the earth, the displacement is normal to the direction of force on the moon. Therefore no work is done by the moon.Work is the dot product of force and displacement.W=F.dcos theta

    Appeared in past papers: 2019

12. 12

    Repeated 7×Work, Power & Energy

    Energy consumed by 60 watt bulb in 2 minutes is equal to:

    • A7.2 kilo joules✓
    • B720 joules
    • C120 joules
    • D72000 joules

    Explanation

    Power=Energy/time Energy=power ×time 60 watt×120 sec =7200 J =7.2 kilo J.

    Appeared in past papers: 2018

13. 13

    Repeated 7×Current Electricity

    Kirchhoff's first law/rule corresponds to:

    • ALaw of conservation of energy
    • BLaw Of conservation Of momentum
    • CLaw of conservation of charge✓
    • DLaw of conservation of mass

    Explanation

    Kirchhoff's first law states that the algebraic sum of current flowing into a junction is zero. This rule corresponds to conservation of charge which states that total charge in a closed system remains constant because current is the rate of flow of charge.

    Appeared in past papers: 2019

14. 14

    Repeated 7×Electrostatics

    Coulomb's law is given by the formula: F=kq1 q2 / r2The magnitude of k having the unit of Nm2 C-2 for free space is equal to

    • A9 x 107
    • B6 x 107
    • C10 x 109
    • D9 x 109✓

    Explanation

    The Coulomb constant, the electric force constant, or the electrostatic constant (denoted ke, k or K) is a proportionality constant in electrostatics equations. In SI units it is equal to 8.9875517923(14)×109 (9*109)kg⋅m3⋅s−2⋅C−2

    Appeared in past papers: 2018

15. 15

    Repeated 7×Forces and Motion

    Which one of the following is a non-conservative force?

    • AElectric force
    • BElastic spring force
    • CGravitational force
    • DFrictional force✓

    Explanation

    Conservative forces, such as gravitational, electric, and elastic spring forces, depend only on the initial and final positions of an object, meaning the work done is independent of the path taken. On the other hand, frictional force is a non-conservative force because the work done by friction depends on the path taken. This is because frictional forces convert kinetic energy into thermal energy, which is dissipated and cannot be recovered, making the process path-dependent.

    Appeared in past papers: 2010

16. 16

    Repeated 7×Electromagnetic Waves

    Which one of the following is not electromagnetic in nature?

    • AX-rays
    • BGamma rays
    • CCathode rays✓
    • DInfrared rays

    Explanation

    Cathode rays EM waves travel with a constant velocity of 3.00x10⁸ ms-1 in vacuum. They are deflected neither by the electric field, nor by the magnetic field. These waves do not require a medium to travel from one place to another. As cathode rays negate all these properties, they are not considered as EM waves.

17. 17

    Repeated 7×Forces and Motion

    Assume that you have two balls of identical volume, one weighing 2 Newtons and the other 10 Newtons. Both are falling freely after being released from the same point simultaneously. Which of the following will then be true: I. The 10 N ball falling freely from rest will be accelerated at a greater rate than the 2 N ball II. At the end of the 4s of freefall, the 10 N ball will have 5 times the momentum of the 2 N ball III. At the end of the 4s of free fall, the 10 N ball will have the same kinetic energy as the 2 N ball IV. The 10 N ball possesses greater inertia than the 2 N ball

    • AI, Il and Ill only
    • BI and II only
    • CII and IV only✓
    • DIV only
    • ENone of these

    Explanation

    Acceleration of free fall acts equally on all masses, this is why both objects despite having different masses have the same speed at any point in time. Statement II is correct because two objects have the same velocity but one having 5 times more mass than the other will have 5 times more momentum than the other object. Statement IV is also correct because inertia depends upon mass since a 10N ball has a higher mass it will have greater inertia. Statement III is wrong because objects have different masses so their kinetic energy can not be the same. Statement I is wrong because objects accele

    Appeared in past papers: 2010

18. 18

    Repeated 7×Electronics

    In a full-wave bridge rectification, the number of diodes used are:

    • A1
    • B2
    • C3
    • D4✓

    Explanation

    A full-wave bridge rectifier consists of 4 diodes arranged in a bridge configuration. This arrangement allows the rectifier to convert both halves of an AC waveform into a pulsating DC output. When the positive half-cycle of the AC input is applied, diodes D1 and D2 conduct, allowing current to flow through the load. During the negative half-cycle, diodes D3 and D4 conduct, again directing current through the load in the same direction. This ensures that the load always receives a unidirectional current. Options A, B, and C are incorrect because they do not provide the necessary number of diod

    Appeared in past papers: 2020

19. 19

    Repeated 7×Magnetism and Electromagnetic Induction

    An electron is moving along the axis of a solenoid carrying a current. Which of the following is a correct statement about the electromagnetic force acting on the electron?

    • AThe force acts radially inwards
    • BThe force acts radially outwards
    • CThe force acts in the direction of motion
    • DNo force acts✓

    Explanation

    The question states along the axis of a solenoid. This implies that the Magnetic feild is parallel to the direction of current (For magnetic force to act, it is necessary that the direction of current and magentic feild are perpendicular to eachother) Therefore, no force acts and electron moves straight through without getting deflected.

    Appeared in past papers: 2017, 2018

20. 20

    Repeated 7×Work, Power & Energy

    Power developed by a person on eating 100g of ice per minute is (Latent heat of ice is 80 cal/g):

    • A130 W
    • B560 cal/sec
    • C560 J/sec✓
    • Dnone of these

    Explanation

    A mass of ice eaten by the man per second. m =100/60=5/3 g/s Latent heat of ice, L = 80 cal/g. Therefore, energy required per second by the man in eating the ice, i.e., power developed by the man. = mL =5/3 x 80 cal/s 3 =5x80/3x4.2J/s=560W

21. 21

    Repeated 7×Wave Motion and Sound

    The path difference for the constructive interference is:

    • A(n-1)λ
    • B(n+1)λ
    • Cn λ / 2
    • D2n λ
    • En λ✓

    Explanation

    Option A: (n-1)λ: This is the path difference for destructive interference. When the path difference is one wavelength less than a whole number of wavelengths, the waves will be out of phase and will cancel each other out. Option B: (n+1)λ: This is also the path difference for destructive interference. When the path difference is one wavelength more than a whole number of wavelengths, the waves will be out of phase and will cancel each other out. Option C: nλ/2: This is the path difference for a node. A node is a point where the waves cancel each other out completely. Option D: 2nλ: This is no

    Appeared in past papers: 2018

22. 22

    Repeated 7×Forces and Motion

    An object moving through a fluid experiences a retarding force known as drag force. The drag force _ as the speed of the object _

    • ADecreases _ Decreases
    • BDecreases _ Increases
    • CIncreases _ Decreases
    • DIncreases_ Increases✓

    Explanation

    Drag is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid.You feel the drag force when you move your hand through the water. You might also feel it if you move your hand during a strong wind. The faster you move your hand, the harder it is to move.Drag force FD is propotional to the square of the speed of the objects. Mathematically,FD = 1/2 C p Av2, Drag force is directly proportional to the square of velocity, so as the speed of the body increases drag force increases.

    Appeared in past papers: 2014, 2015

23. 23

    Repeated 6×Electrostatics

    Electric field strength at a point between oppositely charged plates is 'E'. If the distance between plates is reduced to half, what will be the new value of electric intensity?

    • A4E
    • BE/2
    • CE/4
    • D2E✓

    Explanation

    Between two parallel plates, the electric field strength is given by: E = V/d If the distance is halved, electric field strength is doubled since both are inversely related.

    Appeared in past papers: 2019

24. 24

    Repeated 6×Circular Motion & Momentum

    Work done, due to centripetal force, for circular motion will be:

    • AReduced
    • BZero✓
    • CMaximum
    • DHalf

    Explanation

    The displacement of an object after one complete revolution is 0 as the object returns to its original position. The beginning and final locations of a body that travels a distance and returns to its original place are the same. The displacement is zero in this situation, but the distance travelled is not.As work done = force x displacement, given that the displacement is 0, work done is also 0.

    Appeared in past papers: 2019

25. 25

    Repeated 6×Work, Power & Energy

    In a practical transformer mutual induction between primary and secondary coils takes place. In such transformer what can be deduced about the power.

    • APower output = Power input
    • BPower output > Power input
    • CPower output ≥ Power input
    • DPower output < Power input✓

    Explanation

    The output power in a transformer is always less than the input power because of the different losses in a transformer. The losses may be Iron loss or core loss, hysteresis loss, eddy current loss, copper loss etc.

    Appeared in past papers: 2018

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