41. Pressure gradients has the same dimensions as that of
(A) Energy gradients (B) Velocity gradients
(C) Potential gradients (D) None of these
Ans. (A)
42. Two bodies are known up with initial velocities in the ratio of 2:5. The ratio of the maximum heights by them is
(A) 1:3 (B) 2:7
(C) 3:8 (D) 4:25
Ans. (D)
43. A bullet loses of its velocity after penetrating a plank. How many planks are required to stop the bullet?
(A) 9 (B) 12
(C) 15 (D) 18
Ans. (A)
44. The ceiling of a hall is 25 m. What is the maximum distance at which a ball can be thrown inside the hall?
(A) 50 m (B) 100 m
(C) 150 m (D) 200 m
Ans. (B)
45. Two forces of 12 N and 8 N act upon a body. The resultant force on the body has a maximum value of
(A) 8 N (B) 12 N
(C) 16 N (D) 20 N
Ans. (D)
46. Two bodies of masses m and 4 m are moving with equal kinetic energy. The ratio of their linear momenta is
(A) 1 : 1 (B) 1 : 2
(C) 4 : 1 (D) 1 : 4
Ans. (B)
47. Physical independence of force is a consequence of
(A) First law of motion (B) Second law of motion
(C) Third law of motion (D) None of these
Ans. (A)
48. A motorcyclist double his velocity when he is having a turn. The force exerted outwardly will be
(A) Half (B) Double
(C) 4 times (D) None of these
Ans. (C)
49. When kinetic energy of the body is increased by 300%, the momentum of the body is increased by
(A) 100% (B) 200%
(C) 300% (D) 600%
Ans. (A)
50. An elevator is run by the cables at constant speed ∞. The total work done by the elevator is
(A) Zero
(B) Negative
(C) Positive
(D) Positive or negative depending on the direction of motion
Ans. (B)
51. A disc is rotating with angular speed .If a child sits on it, what is conserved?
(A) Kinetic energy (B) Potential energy
(C) Linear momentum (D) Angular momentum
Ans. (D)
52. To move a body in a circle, which of the following forces is needed?
(A) Centripetal (B) Centrifugal
(C) Gravitational (D) None of these
Ans. (A)
53. Which of the following interactions is the weakest?
(A) Gravitational (B) Electromagnetic
(C) Electrostatic (D) Nuclear
Ans. (A)
54. The colour of star indicates its
(A) Size (B) Velocity
(C) Temperature (D) None of these
Ans. (C)
55. A lift ascending with g/3 acceleration. What will be the time period of a simple pendulum suspended from its ceiling if its period in stationary lift is T?
(A) (B)
(C) T (D)
Ans. (D)
56. A jar has a mixture of H2 and O2 gas in the ratio of 1 : 5. The ratio of mean kinetic energy (K.E.) of H2 and O2 molecules is
(A) 1 : 1 (B) 1 : 2
(C) 1 : 4 (D) 1 : 5
Ans. (A)
57. If S is stress and Y is Young’s modulus of material of a wire, the energy stored per unit volume of the wire is
(A) (B)
(C) (D)
Ans. (D)
58. Freon is most suitable as a refrigerant because of
(A) Small specific heat (B) Small latent heat
(C) Small specific volume (D) Small relative density
Ans. (C)
59. Work done against friction is
(A) An irreversible process (B) Adiabatic process
(C) Isothermal process (D) None of these
Ans. (A)
60. The coefficient of thermal conductivity depends upon
(A) Area of the plate
(B) Thickness of the plate
(C) Nature of the metal
(D) Temperature difference between two sides
Ans. (C)
