CBSE
Multiple Choice QuestionsAccording to kinetic theory of gases, molecules of a gas behave like
inelastic spheres
perfectly elastic rigid spheres
perfectly elastic non-rigid spheres
inelastic non-rigid spheres
A 4 kg roller is attached to a massless spring of spring constant k = 100 N/m. It rolls without slipping along a frictionless horizontal road. The roller is displaced from its equilibrium position by 10 cm and then released. Its maximum speed will be
0.5 m s-1
0.6 m s-1
0.4 m s-1
0.8 m s-1
Assertion: The relative velocity between any two bodies moving in opposite direction is equal to sum of the velocities of two bodies.
Reason: Sometimes relative velocity between two bodies is equal to difference in velocities of the two bodies.
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.
Whenever a stream of electrons collides with a stream of photons, in this collision, which of the following is not conserved?
Linear momentum
Total energy
No. of photons
No. of electrons
Assertion: A quick collision between two bodies is more violent than a slow collision, even when the initial and the final velocities are identical.
Reason: The rate of change of momentum is greater in the first case.
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 spring of spring constant 5 x 103 N m-1 is stretched initially by 5 cm from the unstretched position. The work required to stretch it further by another 5 cm is
6.25 N m
1250 N m
18.75 N m
25.00 N m
Assertion: In elastic collision, kinetic energy is conserved.
Reason: Energy is always conserved.
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 assertion is true but reason is false.
A block of mass 10 kg is moving in x-direction with a constant speed of 10 m/s. It is subjected to a retarding force F = 0·1 x joule /metre during its travel from x= 20 m to x = 30 m. Its final KE will be
475 J
450 J
275 J
250 J
Assertion: Total energy is negative for a bound
system.
Reason: Potential energy of a bound system is
negative and more than kinetic energy.
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.
Assertion: KE is conserved at every instant of (elastic) collision.
Reason: No deformation of matter occurs in elastic collision.
If both assertion and reason are true and reason is correct explanation of assertion.
If both assertion and reason are true but reason is not correct explanation of assertion.
If assertion is true but reason are false.
If both assertion and reason are false.
