10 QA on circular motion | Learn Physics

10 Question – Answer on circular motion

1.       A car takes a turn around a circular curve. If it turns at double the speed, the tendency to overturn is:

(a)    Halved

(b)   Doubled

(c)    Quadrupled

(d)   Unchanged

Ans: (c)

2.       A particle of mass 2 kg is moving along a circular path of radius 1 m. If its angular speed is 2π rad/ s, the centripetal force will be

(a)    4 πN

(b)   4 π² N

(c)    8 πN

(d)   8 π² N

Ans: ( d)

3.       For a particle moving along a circular path with a constant speed, the acc. Is constant in:

(a)    Magnitude

(b)   Direction

(c)    Both magnitude and direction

(d)   neither magnitude nor direction

Ans : ( a)

4.       A stone is tied to the end of string of length l and is whirled along a circular path. What happens when the string breaks?

(a)    Stone flies radially inwards

(b)   Stone flies radially outwards

(c)    Stone drops down

(d)   Stone flies along the tangent to the circular path

Ans : (d)

5.       A car is moving along a circular road at a speed of 20 m/s. the radius of the circular road is 10 m. If the speed is increased at the rate of 30 m/s², what is the resultant acc. ?

(a)    10 m/s²

(b)   50 m/s²

(c)    250 m/s²

(d)   80 m/s²

Ans: ( b)

6.       A car of mass 2000 kg is moving with a speed of 10 m/s on circular path of radius 20 m on a level road. What must be the frictional force between the car and road so that the car does not slip?

(a)    10⁴  N

(b)   10³  N

(c)    10⁵  N

(d)   10²  N

Ans: (a)

7.       A car of mass 1000 kg moves on a circular track of radius 20 m. If the coefficient of friction is 0.64, then the max. Velocity with which the car can move is ?

(a)    22.4 m/s

(b)   5.6 m/s

(c)    11.2 m/s

(d)   None of above

Ans:( c )

8.       A body of mass m tied to a string is moved in a vertical circle of radius r. The difference in tensions at the lowest point and the highest point is:

(a)    2 mg

(b)   6 mg

(c)    4 mg

(d)   8 mg

Ans: ( b)

9.       A motor cyclist loops the loop whose diameter is 8 m. From what minimum height must he start in order to roll down and go around the loop?

(a)    10 m

(b)   8 m

(c)    80 m

(d)   0.8 m

Ans: (a)

                     10.  Find the minimum speed of a bike at a highest point of a globe of diameter 19.6 m

(a)    9.8 m/s

(b)   19.6 m/s

(c)    4.9 m/s

(d)   39.2 m/s

Ans: ( a)