set 4 MCQ Questions & Answers Detailed Explanation

Question : 1

A system of masses connected by a string, passing over pulleys A and B as shown in the figure. The pulleys are massless. Match the columns : (Take g = 10 m/$s^2$)

a) A – 2 ; B – 3 ; C – 1

b) A – 2 ; B – 4 ; C – 1

c) A – 1 ; B – 2 ; C – 3

d) A – 4 ; B – 3 ; C – 2

Question : 2

A jet plane moves up in air because

a) the flow of air around the wings causes an upward force, which compensates for the force of gravity

b) the thrust of the jet compensates for the force of gravity

c) the gravity does not act on bodies moving with high speeds

d) the weight of air whose volume is equal to the volume of the plane is more than the weight of the plane

Question : 3

A man is standing on a sensitive balance. If he inhales deeply, the reading of the balance

a) Remains unaffected

b) Decreases

c) Increases

d) May increase or decrease depending on the atmospheric pressure

Question : 4

Gravitational potential energy of an object will

a) not effected by changing the path, provided the overall height is same

b) decrease by increasing the path along which the object is moved

c) increase by increasing the path along which the object is moved

d) None of these

Question : 5

A man getting down a running bus, falls forward because-

a) he leans forward as a matter of habit

b) due to inertia of motion upper part of body continues to be in motion in forward direction while feet come to rest as soon as they touch the road

c) due to inertia of rest, road is left behind and man reaches forward

d) of the combined effect of all the three factors stated in (a), (b) and (c)

Question : 6

A particle is moving in a circular path of radius r. The displacement after half a circle would be

a) 2 r

b) pr

c) zero

d) 2pr