# MCQs of Physics for Medical Entrance Preparation (Part 1)

Here, we present some of the MCQs related to physics that can be helpful for the students who are preparing for various medical subjects like MBBS, BDS, nursing, engineering and so on.

1. Which of the following pairs of physical quantities does not have same dimensional formula?

• work and torque
• angular momentum and Planck’s constant
• tension and surface tension
• impulse and linear momentum

2. Which of the following quantities has a unit but dimensionless?

• strain
• Reynolds number
• angular displacement
• Poisson’s ratio

3. Random error can be eliminated by:

• careful observation
• eliminating the cause
• measuring the quantity with more than one instrument
• taking large number of observations and their mean

4. If velocity (V), time (t)and force (F) are fundamental quantities, what is the dimensional formula for mass:

• [F-1TV]
• [FTV]
• [FVT-1]
• [F-1TV-1]

5. The sum of the numbers 436.32, 227.2 and 0.301 in appropriate significant figures is

• 6663.821
• 664
• 663.8
• 663.8

6. If the dimensions of critical velocity Vc of a liquid flowing through a tube are expressed as [ηxρyrz], where η, ρ and r are the coefficient of viscosity of liquid, density of liquid and radius of the tube respectively, then the values of x, y and z are given by:

• -1, -1, 1
• -1,  -1, -1
• 1, 1, 1
• 1, -1, -1

7. Mass of a body is 210gm and its density is 7.981 g/cm3 .what will be its volume, with regard to significant digits

• 26. 312 cm3
• 26 cm3
• 27 cm3
• 26.3 cm3

8. The percentage error in the measurement of length of the cube is 2%, what will be the percentage error in the measurement of its volume?

• 2%
• 1%
• 4%
• 6%

9. The unit of permittivity of free space , ε0 is

• Coulomb2/(Newton-metre)2
• Coulomb/Newton-metre
• Newton-metre2/Coulomb2
• Coulomb2/Newton-metre2

10. Which of the following is dimensional constant?

• refractive index
• poisson’s ratio
• crelative density
• gravitational constant

11. The dimensions of (µ0ε0)-1/2 are

• [L1/2T-1/2]
• [L-1T]
• [LT-1]
• [L-1/2T1/2]

12. The ratio of dimensions of Planck’s constant and that of the moment of inertia is the dimension of

• time
•  frequency
• angular momentum
• velocity

13.Which of the following sets cannot be taken as fundamental quantities in any system of units:

• length, mass , velocity
• length, time, velocity
• mass, time acceleration
• energy, force, time

14. The solid angle sustended by the total surface area of a sphere, at the centre is

• 4π
• π

15. The dimensional formula of torque is

• [ML2T-2]
• [MLT-2]
• [ML-1T-2]
• [ML-2T-2]

16. The least count of a stop watch is 0.2 second. The time of 20 oscillations of a pendulum is measured to be 25 seconds. The percentage error in the measurement of time will be

• 8%
• 1.8%
• 0.8%
• 0.1%

17. If the dimensions of physical quantity are given by MaLbTc, then the physical quantity will be:

• velocity if a=1, b= 0, c= -1
• acceleration if a= 1, b= 1, c= -2
• force if a= 0, b= -1, c= -2
• pressure if a= 1, b= -1, c= -2

18. If f= x2, then the relative error in f is

• 2Δx/x
• (Δx)2/x
•  Δx/x
• (Δx)2

19. Two quantities A and B have different dimensions. Which mathematical operation given below is physically meaningful?

• A/B
• A+B
•  A-B
• A=B

20. In a vernier caliper, N divisions of vernier scale coincide with (N-1) divisions of main scale (in which length of one division is 1 mm). The least count of the instrument should be

• N
• N-1
•  1/10N
• 1/N-1

21. The speed of a sound in gas is given by V= √(γP/d) where P is pressure and d is density. The dimensional formula for γ is

• M-1L1T2
• M0L0T0
• M0L-1T0
• M0L0T1

22. In a simple pendulum experiment, the maximum percentage error in the measurement of length is 2% and that in the observation of the time-period is 3%. Then, the maximum percentage error in determination of the acceleration due to gravity g is

• 5%
• 6%
•  1%
• 8%

23. A force is given by F= at +bt2, where ‘t’ is time, the dimensions of a and b are

• [MLT-4] and [MLT-1]
• [MLT-1] and [MLT0]
• [MLT-3] and [MLT-4]
• [MLT-3] and [MLT0]

24. If P, Q, R are physical quantities, having different dimensions, which of the following combinations can never be a meaningful quantity?

• (P-Q)/R
• PQ-R
• PQ/R
•  (PR-Q2)/R

25. The physical quantities not having the same dimensions are

• torque and work
• momentum and Planck’s constant
• stress and Young’s modulus
• speed and (µ0ε0)-1/2

26. Which one of the following represents the correct dimensions of the gravitational constant?

• [M-1L3T-2]
• [MLT-1]
• [ML-1T-2]
• [ML-2T-2]

27. If the capacitance of a nano-capacitor is measured in terms of a unit ‘u’ made by combining the electric charge ‘e’, Bohr radius ‘a0’, Planck’s constant ‘h’ and speed of light ‘c’, then

• u= e2h/a0
• u= hc/e2a0
•  u= e2c/ha0
• u= e2a0/hc

28. A stone falls freely under gravity. It covers distances h1, h2 and h3 in the first 5 seconds, the next 5 seconds and the next 5 seconds respectively. The relation between h1, h2 and h3 is

• h1= h2/3= h3/5
• h2= 3h1 and h3= 3h2
• h1= h2= h3
• h1= 2h2= 3h3

29. A particle moves a distance x in time t according to equation x= (t + 5)-1. The acceleration of particle is proportional to:

• (velocity)3/2
• (distance)2
• (distance)-2
• (velocity)2/3

30. Two bodies, A (of mass 1 kg) and B (of mass 3 kg), are dropped from height of 16m and 25m, respectively. The ratio of the time taken by them to reach the ground is

• 12/5
• 5/12
• 4/5
• 5/4

31. What is the relation between displacement, time and acceleration in case of a body having uniform acceleration?

• S= ut + ½ at2
• S= (u + a)t
• S= v2 -2as
• none of these

32. The displacement of a particle is represented by the following equation: s= 3t3 +7t2+ 5t + 8 where s is in metre and t in second. The acceleration of the particle at t= 1s is

• 14 m/s2
• 18 m/s2
• 32 m/s2
• zero

33. A body starts from rest, what is the ratio of the distance travelled by the body during the 4th and 3rd seconds?

• 7/5
• 5/7
• 7/3
• 3/7

34. If the velocity of the particle is v= At + Bt2, where A and B are constants, then the distance travelled by it between 1s and 2s is:

• (3/2)A + 4B
• 3A + 7B
• (3/2)A + (7/3)B
• (A/2)+ (B/3)

35. The area of the acceleration-displacement curve of a body gives

• impulse
• change in momentum per unit mass
• change in KE per unit mass
• total change in energy

36. At a metro station, a girl walks up a stationary escalator in time t1. If she remains stationary on the escalator, then the escalator takes her up in time t2. The time taken by her to walk up on the moving escalator will be

• (t1 + t2)/2
• t1t2/(t2 – t1)
• t1t2/(t2 + t1)
• t1 – t2

37. The slope of the velocity time graph for retarded motion is

• positive
• negative
• zero
• can be +ve, -ve or zero.

38. The displacement of a body is zero. The distance covered

• is zero
• is not zero
• may or may not be zero
• depends on the acceleration

39. Which one of the following statement is false?

• a body can have zero velocity and still be accelerated
• a body can have a constant velocity and still have a varying speed
• a body can have a constant speed and still have a varying velocity
• the direction of the velocity of a body can change when its acceleration is constant

40. A particle has moved from one position to another position

• its distance is zero
• its displacement is zero
• neither distance nor displacement is zero
• average velocity is zero

41. A vehicle travels half the distance with speed V1 and the other half with speed V2, then its average speed is:

• (V1 + V2)/2
• (2V1 + V2)/(V1 + V2)
• 2V1 V2/(V1 + V2)
• 2(V1+ V2)/V1V2

42. The study of motion without consideration of its cause is studied in

• statistics
• kinematics
•  mechanics
• modern physics

43. The displacement of a particle starting from rest (at t= 0) is given by s= 6t2 – t3. The time in seconds at which the particle will attain zero velocity again, is:

• 2
• 4
• 6
• 8

44. The ratio of the numerical values of the average velocity and average speed of a body is always:

• unity
• unity or less
• unity or more
• less than unity

45. Which of the following changes when a particle is moving with uniform velocity?

• speed
• velocity
• acceleration
• position vector

46. A lift is coming from 8th floor and is just about to reach 4th Taking ground floor as origin and positive direction upwards for quantities, which one of the following is correct?

• X<0, v<0, a>0
• X>0, v<0, a<0
• X>0, v<0, a>0
• X>0, v>0, a<0

47. A point travelled half of the distance with velocity v0. The half of remaining part of the distance was covered with velocity v1 and second half of remaining part by v2 The mean velocity of the point, averaged over whole time of motion is

• (v0 + v1 + v2)/3
• (2v0 + v1 + v2)/3
• (v0 +2v1 +2v2)/3
• 2v0(v1 + v2)/(2v0 + v1 + v2)

48. From a tower of height ‘H’, a particle is thrown vertically upwards with a speed ‘u’. The time taken by the particle to hit the ground is ‘n’ times that taken by it to reach the highest point of its path. The relation between H, u and n is

• 2gH = n2u2
• gH = ( n – 2)2 u2d
• 2gH = nu2 ( n – 2)
• gH = ( n -2)u2

49. A car accelerates from rest at a constant rate ‘α’ for some time after which it decelerates at a constant rate ‘β’ to come to rest. If the total time elapsed is ‘t’, the maximum velocity acquired by the car is given by

• 2 + β2)/αβ)t
• 2 – β2)/αβ)t
• (α + β)/αβ)t
• (αβ/(α + β))t

50. A particle moves along a straight line OX. At a time t (in second) the distance x (in metre) of the particle from O is given by x = 40 + 12t –t3. How long would the particle travel before coming to rest?

• 24m
• 40m
•  56m
• 16m

51. A body is projected vertically upwards. If ‘t1’ and ‘t2’ be the times at which it is at height ‘h’ above the projection while ascending and descending respectively, then ‘h’ is

• ½ gt1t2
• gt1t2
• 2 gt1t2
• 2hg