**Q1** **which of the following pairs do not match :-**

a) rotational power-Joule/sec

b) torque-Newton meter

c) angular displacement-radian

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

d) blade

**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. **

a) the radius

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

**ANSWERS **

**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**