Physics - 13

61. An iron ball and a wooden ball of the same mass are released from a height h in air. Neglecting viscous drag of air

(A) There is an equal probability for the wooden and iron ball to hit the ground earlier.

(B) Both will reach the ground at the same time.

(C) The iron ball will hit the ground earlier.

(D) The wooden ball will hit the ground earlier

(A) There is an equal probability for the wooden and iron ball to hit the ground earlier.

(B) Both will reach the ground at the same time.

(C) The iron ball will hit the ground earlier.

(D) The wooden ball will hit the ground earlier

Correct Answer: [B] Both will reach the ground at the same time..

62. When the angle of incidence is equal to the critical angle for the media, the angle of refraction is

(A) 45°

(B) 90°

(C) 0°

(D) Angle of incidence

(A) 45°

(B) 90°

(C) 0°

(D) Angle of incidence

Correct Answer: [B] 90°.

63. Greenhouse effect causes

(A) lowering in temp. of the earth.

(B) continuous snowing on the earth.

(C) rise in temperature of the earth.

(D) continuous rainfall

(A) lowering in temp. of the earth.

(B) continuous snowing on the earth.

(C) rise in temperature of the earth.

(D) continuous rainfall

Correct Answer: [C] rise in temperature of the earth..

64. Two ends of a tube are closed by corks so that the tube become airtight. The pressure of air inside the closed tube is

(A) Equal to the atmospheric pressure.

(B) Dependent on the length of the tube.

(C) Very small.

(D) Slightly less than the atmospheric pressure

(A) Equal to the atmospheric pressure.

(B) Dependent on the length of the tube.

(C) Very small.

(D) Slightly less than the atmospheric pressure

Correct Answer: [A] Equal to the atmospheric pressure..

65. The ratio of the velocity of a body to the velocity of sound is called

(A) Natural number

(B) Mach number

(C) Magic number

(D) Laplace number

(A) Natural number

(B) Mach number

(C) Magic number

(D) Laplace number

Correct Answer: [B] Mach number.

## 0 Comments:

## Post a Comment