G-MS2D75B7RR

# Worksheet on Rotational Motion

Q1 which of the following pairs do not match :-

a) rotational power-Joule/sec

b) torque-Newton meter

d) angular acceleration - radian/sec

Q2 All the particles of a rigid rotating body move in a circular path when the axis of rotation:-

a) passes through any point in body

b) is situated outside the body

c) situated anywhere

d) passes through the centre of mass

Q3 On account of the earth rotating about its axis :-

a) the linear velocity of objects at equator is greater than at other places.

b) the angular velocity of objects at equator is more than that of objects at poles.

c) the linear velocity of objects at all places at the earth is equal, but angular velocity is different.

d) at all places the angular velocity and linear velocity are uniform.

Q4 The quantity not involved directly in rotational motion of the body is

a) moment of inertia

b) torque

c) angular velocity

d) mass

Q5 The moment of inertia of a body about a given axis of rotation depends upon :-

a) the distribution of mass

b) distance of particle of body from the axis of rotation

c) shape of the body

d) all of the above

Q6 A flywheel is so constructed that almost whole of its mass is concentrated at its rim, because:-

a) it increases the moment of inertia of the fly-wheel

b) it decreases the moment of inertia of the fly-wheel

c) it increases the speed of the fly-wheel

d) it increases the power of the fly-wheel

Q7 The wheels of moving vehicles are made hollow in the middle and thick at the periphery, because

a) it gives minimum moment of inertia to the tyre

b) its shape is a strong one

c) this increases the speed

d) it increases moment of inertia of tyre

Q8 The theorem of perpendicular axes is not applicable for determination of moment of inertia along the diameter, for which of the following body :-

a) sphere

b) disc

c) ring

Q9 Which of the following has the highest moment of inertia when each of them has the same mass and the same radius?

a) a hollow sphere about one of its diameters

b) a solid sphere about one of its diameters

c) a disc about its central axis perpendicular to the plane of the disc

d) a ring about its central axis perpendicular to the plane of the ring.

Q10 The moment of inertia in rotational motion is equivalent to :-

a) angular velocity of linear motion

b) mass of linear motion

c) frequency of linear motion

d) current

Q11 Moment of inertia :-

a) is a vector quantity

b) is a scalar quantity

c) is a tensor quantity

d) can not be calculate

Q12 Which of the following bodies of same mass and same radius has minimum moment of inertia?

a) Ring

b) Disc

c) Hollow sphere

d) Solid sphere

Q13 A ring and a solid sphere of same mass and radius are rotating with the same angular velocity about their diameteric axes then ;-

a) it is easier to stop the ring

b) it is easier to stop the solid sphere

c) it is equally difficult to stop both of them

d) it is not possible to stop a rotating body

Q14 A rigid body is rotating about an axis. To stop the rotation, we have to apply :-

a) pressure

b) force

c) momentum

d) torque

Q15 When constant torque is acting on a body then :-

a) body maintain its state or moves in straight line with same velocity

b) acquire linear acceleration

c) acquire angular acceleration

d) rotates with a constant angular velocity

Q16 If torque on a body is zero, then which is conserved:

a) force

b) linear momentum

c) angular momentum

d) angular impulse

Q17 If a ladder is not in balance against a smooth vertical wall, then it can be made in balance by :-

a) Decreasing the length of ladder

b) Increasing the length of ladder

c) Increasing the angle of inclination

d) Decreasing the angle of inclination

Q18 When a mass is rotating in a plane about a fixed point, its angular momentum is directed along.

b) the tangent to orbit

c) line at an angle of 45 degree to the plane of rotation

d) the axis of rotation

Q19 In an orbital motion, the angular momentum vector is :-

a) along the radius vector

b) parallel to the linear momentum

c) in the orbital plane

d) perpendicular to the orbital plane

Q20 On melting of ice on the pole of the earth, its moment of inertia will :-

a) increase

b) decrease

c) remain unchanged

d) none of these

Q21 If the earth loses its atmosphere suddenly, then the duration of day will :-

a) increase

b) decrease

c) remain unchanged

d) nothing can be definitely said

Q22 A wheel is rotating about its axis at a constant angular velocity. If suddenly an object sticks to it on the rim, then its M.I. will :-

a) increase

b) decrease

c) remain unchanged

d) nothing can be said

Q23 The angular momentum of body remains conserve if :-

a) applied force on body is zero.

b) applied torque on body is zero.

c) applied force on body is constant.

d) applied torque on body is constant.

Q24 Rate of change of angular momentum with respect to time is proportional to :-

a) angular velocity

b) angular acceleration

c) moment of inertia

d) torque

Q25 If the earth were to suddenly contract to half its present size, without any change in its mass, the duration of the new day will be

a) 18 hours

b) 30 hours

c) 6 hours

d) 12 hours

Q26 A ring is rolling without slipping. Its energy of translation is E. Its total kinetic energy will be :-

a) E

b) 2E

c) 3E

d) 4E

Q27 A solid sphere of mass M and radius R rolls on a horizontal surface without slipping. The ratio of rotational K.E. to total K.E. is :-

a) 1/2

b) 3/7

c) 2/7

d) 2/10

Q28 If rotational kinetic energy is 50% of total kinetic energy then the body will be :-

a) ring

b) cylinder

c) hollow sphere

d) solid sphere

Q29 If the angular velocity of a body rotating about an axis is doubled and its moment of inertia halved, the rotational kinetic energy will changed by a factor of :-

a) 4

b) 2

c) 1

d) 1/2

1) d

2) b

3) a

4) d

5) d

6) a

7) d

8) a

9) d

10) b

11) c

12) d

13) b

14) d

15) c

16) c

17) c

18) d

19) d

20) a

21) b

22) a

23) b

24) d

25) c

26) b

27) c

28) a

29) b