2022Flame Institute

(a) Weight becomes zero, but not the mass (b) Mass becomes zero, but not the weight (c) Both mass and weight become zero (d) Neither mass nor weight become zero Answer: a (7)

At what height from the ground will the value of ‘g’ be the same as that in 10 km deep mine below the surface of earth

(a) 20 km (b) 10 km (c) 15 km (d) 5 km Answer: a (9)

Acceleration due to gravity is ‘g’ on the surface of the earth. The value of acceleration due to gravity at a height of 32 km above earth’s surface is (Radius of the earth = 6400 km)

(a) 0.9 g (b) 0.99 g (c) 0.8 g (d) 1.01 g Answer: b (10)

What should be the velocity of earth due to rotation about its own axis so that the weight at equator become 3/5 of initial value. Radius of earth on equator is 6400 km

(a) 7.4 × 10-4 rad /sec (b) 6.7 × 10-4 rad /sec (c) 7.8 × 10-4 rad /sec (d) 8.7 10-4 …

Mass of moon is 7.34 ×1022 kg. If the acceleration due to gravity on the moon is 1.4 m/s2 , the radius of the moon is (G = 6.667×10-11 Nm2 /kg2)

(a) 0.56 × 104 (b) 1.87 × 106 (c) 1.92 × 106 (d) 1.01 × 108 Answer: b (6)

If mass of a body is M on the earth surface, then the mass of the same body on the moon surface is

(a) M/6 (b) Zero (c) M (d) None of these Answer: c (5)

If radius of the earth contracts 2% and its mass remains the same, then weight of the body at the earth surface

(a) Will decrease (b) Will increase (c) Will remain the same (d) None of these Answer: b (13)

If the radius of the earth shrinks by 1.5% (mass remaining same), then the value of acceleration due to gravity changes by

(a) 1% (b) 2% (c) 3% (d) 4% Answer: c (5)

Where will it be profitable to purchase 1 kilogram sugar

(a) At poles (b) At equator (c) At 45° latitude (d) At 40° latitude Answer: b (8)

24. Assertion : A body subjected to three concurrent forces cannot be in equilibrium. Reason : If large number of concurrent forces acting on the same point, then the point will be in equilibrium, if sum of all the forces is equal to zero.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. (b) If both assertion and reason are true but reason is not the correct explanation of the assertion. (c) If assertion is …

25. Assertion : Impulse and momentum have different dimensions. Reason : From Newton’s second law of motion, impulse is equal to change in momentum.

23. Assertion : A table cloth can be pulled from a table without dislodging the dishes. Reason : To every action there is an equal and opposite reaction.

22. Assertion : A reference frame attached to earth is an inertial frame of reference. Reason : The reference frame which has zero acceleration is called a non inertial frame of reference.

21. Assertion : Newton’s third law of motion is applicable only when bodies are in motion. Reason : Newton’s third law applies to all types of forces, e.g. gravitational, electric or magnetic forces etc.

Let g be the acceleration due to gravity at earth’s surface and K be the rotational kinetic energy of the earth. Suppose the earth’s radius decreases by 2% keeping all other quantities same, then

(a) g decreases by 2% and K decreases by 4% (b) g decreases by 4% and K increases by 2% (c) g increases by 4% and K increases by 4% (d) g decreases by 4% and K increases by 4% …