Laws Of Motion CBSE Questions & Answers

Laws Of Motion

This is Physics Class 11 Laws of Motion CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
force is required
  • A
    only to start a stationary object moving
  • B
    only to stop a moving object
  • C
    only to keep an object moving
  • D
    to start a stationary object, sometimes to keep an object moving and to stop a moving object
    Correct
2
According to first law of motion
  • A
    body acted on by zero net force moves with non zero acceleration
  • B
    body acted on by no net force moves with increasing velocity and negative acceleration
  • C
    body acted on by net force moves with constant velocity (which may be zero)
  • D
    body acted on by no net force moves with constant velocity (which may be zero) and zero acceleration
    Correct
3
Inertia refers to
  • A
    slow motion
  • B
    dullness
  • C
    resistance to change
    Correct
  • D
    ease of motion
4
Momentum of a body is
  • A
    a scalar equal in magnitude to the product of mass and velocity
  • B
    a vector equal in magnitude to the product of mass and instantaneous velocity and direction being that of instantaneous velocity
    Correct
  • C
    a vector equal in magnitude to the product of mass and acceleration and direction being that of velocity
  • D
    a vector equal in magnitude to the product of mass and average speed and direction being that of velocity
5
According to second law of motion
  • A
    The momentum of a body is directly proportional to the applied force and takes place in the direction in which the force acts
  • B
    The rate of change of momentum of a body is directly proportional to the applied force and takes place in the direction in which the force acts
    Correct
  • C
    The change of momentum of a body is directly proportional to the applied force and takes place in the direction in which the force acts
  • D
    The momentum of a body is directly proportional to the applied force and takes place in the direction opposite to the force
6
Force is a
  • A
    qualitative measure of the momentum of two bodies
  • B
    quantitative measure of the interaction between two bodies
    Correct
  • C
    qualitative measure of the interaction between two bodies
  • D
    quantitative measure of the momentum between two bodies
7
Second law in terms of momentum p and mass m is
  • A
    \(F = kpp\)
  • B
    \(F = kp{{dp} \over {dt}}\)
  • C
    \({\rm{}}F = kp\)
  • D
    \(F = k{{dp} \over {dt}}\)
    Correct
8
For a body of fixed mass second law in terms of acceleration a and mass m is
  • A
    F = m a. a
  • B
    F = \({{\rm{m}}^{\rm{2}}}\) a
  • C
    F = m a
    Correct
  • D
    F = k \({{\rm{m}}^{ - {\rm{1}}}}\) a
9
When several forces act on a body
  • A
    the effect on its motion is the same as when a single force, equal to the vector sum (resultant) of the forces, acts on the body
    Correct
  • B
    the effect on its motion is the same as when a single force acts on the body
  • C
    the effect on its motion is the same as when a single force acts on the body
  • D
    the effect on its motion is the same as when a single force, not equal to the vector sum (resultant) of the forces, acts on the body
10
If a body is in equilibrium
  • A
    \(\mathop \sum \nolimits^ F\)< 0
  • B
    \(\mathop \sum \nolimits^ F\)depends on time
  • C
    \(\mathop \sum \nolimits^ F\)= 0
    Correct
  • D
    \(\mathop \sum \nolimits^ F\)> 0
11
The second law of motion is a vector law. It is equivalent to
  • A
    One equation, one for each component of the vectors
  • B
    Two equations, one for each component of the vectors
  • C
    Four equations, one for each component of the vectors and one for time
  • D
    Three equations, one for each component of the vectors
    Correct
12
If second law is applied to a rigid body
  • A
    the acceleration is the average of all particles in the body
  • B
    the acceleration is that of any particle in the body
  • C
    none of the above
  • D
    the acceleration is that of the centre of mass
    Correct
13
Force F at a point in space (location of the particle) at a certain instant of time t is
  • A
    related to acceleration a at that point at previous instant.
  • B
    related to acceleration a at previous point at that instant.
  • C
    related to acceleration a at that point at that instant.
    Correct
  • D
    related to acceleration a at that point at next instant.
14
The force acting on a freely falling body in terms of mass m and acceleration due to gravity g is
  • A
    F = m \({{\rm{g}}^{\rm{2}}}\)
  • B
    F = \({{\rm{m}}^{ - {\rm{2}}}}\) g
  • C
    F = \({{\rm{m}}^{\rm{2}}}\) g
  • D
    F = m g
    Correct
15
Impulse is
  • A
    the difference of force over a short period
  • B
    the derivative of force over a short period
  • C
    the average of force over a short period
  • D
    the integral of force over a short period
    Correct