Angular Velocity

Q. The direction of the angular velocity vector is along

1. none of these.
2. the radial direction.
3. the axis of rotation.
4. the tangential direction.

Q.

A car is going with constant speed on a circular path. If it starts from point A at t = 0 and reaches diametrically opposite point B after 2 sec then find its angular velocity.

1. 

2. 

3. 

4. 

Q.

The angular velocity of a particle rotating in a circular orbit 100 times per minute is

1. 1.66 rad/s

2. 10.47 rad/s

3. 60 deg/s

4. 10.47 deg/s

Q. Two cars having masses $m_{1}and{m}_2$ move in circles of radii $r_{1}and{r}_2$ respectively. If they complete the circle in equal time, the ratio of their angular speeds $\frac{{\omega }_1}{{\omega }_2}$ is _______

1. 1

2. 

3. 

4. 

Q.

A particle comes round a circle of radius 1 m once. The time taken by it is 10 sec. The average velocity of motion is

1. Zero

2. $0.2\pi m/s$

3. $2\pi m/s$

4. $2m/s$

Q.

If a particle moves in a circle describing equal angles in equal times, its velocity vector

1. Changes both in magnitude and direction

2. Changes in direction

3. Changes in magnitude

4. Remains constant

Q.

In uniform circular motion

1. Both the angular velocity and the angular momentum vary

2. Both the angular velocity and the angular momentum stay constant

3. The angular momentum varies but the angular velocity remains constant

4. The angular velocity varies but the angular momentum remains constant

Q.

The ratio of angular speeds of minute hand and hour hand of a watch is

1. 1 : 12

2. 12 : 1

3. 6 : 1

4. 1 : 6

Q.

In 1.0 s, a particle goes from point A to point B, moving in a semicircle of radius 1.0 m (see figure). The magnitude of the average velocity is

1. 3.14 m/s

2. 2.0 m/s

3. 1.0 m/s

4. Zero

Q.

A fan is rotating with angular velocity 100 revs/sec. Then it is switched off. It takes 5 minutes to stop.
(i) Find the total number of revolutions made before it stops. (Assume uniform angular retardation)
(ii) Find the value of angular retardation.
(iii) Find the average angular velocity during this interval.

1. (i) $15000revs$
   (ii) $\frac{1}{3}rev/s^2$
   (iii) $50revs/s$

2. (i) $1500revs$
   (ii) $\frac{1}{2}rev/s^2$
   (iii) $50revs/s$

3. (i) $10000revs$
   (ii) $\frac{1}{2}rev/s^2$
   (iii) $50revs/s$

4. (i) $12000revs$
   (ii) $\frac{1}{6}rev/s^2$
   (iii) $75revs/s$