CBSE
Multiple Choice QuestionsA body of mass 2m is placed on earth's surface. Calculate the change in gravitational potential energy, if this body is taken from earth's surface to a height of h, where h = 4R.
Assertion: Two bodies of masses M and m (M > m) are allowed to fall from the same height if the air resistance for each be the same then both the bodies will reach the earth simultaneously.
Reason: For same air resistance, acceleration of both the bodies will be same.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
A person is standing in an elevator. In which situation he finds himself weightless?
Elevator is going up with constant speed.
Elevator is moving down with constant speed.
Elevator is accelerating up with g.
Elevator is accelerating down with g.
Time period of pendulum, on a satellite orbiting the earth, is
zero
infinity
What will be the effect on the weight of a body placed on the surface of earth, if earth suddenly ' stops rotating?
No effect
Weight will increase
Weight will decrease
Weight will become zero
A satellite is in an orbit around the earth. If its kinetic energy is doubled, then
it will maintain its path
it will fall on the earth
it will rotate with a great speed
it will escape out of earth's gravitational field
The change in the gravitational potential energy when a body of mass m is raised to a height nR above the surface of the earth is ( here R is the radius of the earth )
nn + 1 mgR
nn - 1 mgR
nmgR
mgRn
Assertion: Kepler's second law can be understood by conservation of angular momentum principle.
Reason: Kepler's second law is related with areal velocity which can further be proved to be based on conservation of angular momentum as (dA/dt) = ( r2ω / 2 )
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false
The additional kinetic energy to be provided to a satellite of mass m revolving around a planet of mass M to transfer it from a circular orbit of radius R, to another of radius R2 (R2 > R1 ) is
GmM
GmM
2 GmM
GmM
A communication satellite of 500 kg revolves around the earth in a circular orbit of radius 4.0 x 107 m in the equatorial plane of the earth from west to east. The magnitude of angular momentum of the satellite is
∼ 0.13 × 1014 kg m2 s-1
∼ 1.3 × 1014 kg m2 s-1
∼ 0.58 × 1014 kg m2 s-1
∼ 2.58 × 1014 kg m2 s-1
