ShilpaFlame Institute

Two particles of equal mass go round a circle of radius R under the action of their mutual gravitational attraction. The speed of each particle is

(a) v = 1/2R √1/gm (b) v =√gm /2R (c) v=1/2√gm/R (d) v=√4gm/R Answer: c (7)

9. Assertion : The slope of momentum versus time curve give us the acceleration. Reason : Acceleration is given by the rate of change of momentum

(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 …

8. Assertion : Mass is a measure of inertia of the body in linear motion. Reason : Greater the mass, greater is the force required to change its state of rest or of uniform motion.

7. Assertion : No force is required by the body to remain in any state. Reason : In uniform linear motion, acceleration has a finite value.

6. Assertion : Aeroplanes always fly at low altitudes. Reason : According to Newton’s third law of motion, for every action there is an equal and opposite reaction.

5. Assertion : If two objects of different masses have same momentum, the lighter body possess greater velocity. Reason : For all bodies momentum always remains same.

4. Assertion : Force is required to move a body uniformly along a circle. Reason : When the motion is uniform, acceleration is zero.

1. Assertion : Inertia is the property by virtue of which the body is unable to change by itself the state of rest only. Reason : The bodies do not change their state unless acted upon by an unbalanced external force.

Read the assertion and reason carefully to mark the correct option out of the options given below: (a) If both assertion and reason are true and the reason is the correct explanation of the assertion. (b) If both assertion and …

2. Assertion : If the net external force on the body is zero, then its acceleration is zero. Reason : Acceleration does not depend on force.

3. Assertion : Newton’s second law of motion gives the measurement of force. Reason : According to Newton’s second law of motion, force is directly proportional to the rate of change of momentum.

The gravitational force between two stones of mass 1 kg each separated by a distance of 1 metre in vacuum is

(a) Zero (b) 6.675×10-5 newton (c) 6.675×10-11 newton (d) 6.675×10-8 newton Answer: c (8)

7. Which of the following is the evidence to show that there must be a force acting on earth and directed towards the sun

(a) Deviation of the falling bodies towards east (b) Revolution of the earth round the sun (c) Phenomenon of day and night (d) Apparent motion of sun round the earth Answer: b (4)

The atmosphere is held to the earth by

(a) Winds (b) Gravity (c) Clouds (d) None of the above Answer: b (7)

A satellite of the earth is revolving in a circular orbit with a uniform speed v. If the gravitational force suddenly disappears, the satellite will

(a) Continue to move with velocity v along the original orbit (b) Move with a velocity v, tangentially to the original orbit (c) Fall down with increasing velocity (d) Ultimately come to rest somewhere on the original orbit Answer: b …