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01-A car of 1000 kg travelling at 20 m/s rounds a curve of radius 100 m. Find the necessary centripetal force:

4 x 10^3 kg m/s^2

3 x 10^3 kg m/s^2

5 x 10^3 kg m/s^2

4.5 x 10^3 kg m/s^2

02-Angular speed of a particle increases from 2 rad/s to 4 rad/s across any two diametrically opposite positions. Its angular acceleration will be?

6 rads^-2

6/pi rads^-2

Pi/6 5 rads^-2

Pi rads^-2

03-Particle is moving in a circle of radius r with constant angular speed w. Its acceleration directed towards the centre of the circle is:

W/ r

W^2/ r

W^2 r

W r^2

04-When a particle moves in a circle, the angle between its linear velocity and angular velocity is always:

90'

180'

Pi radians

05-The angular speed in radian/hour for daily rotation of the earth is:

2 pi

Pi/6

4 pi

Pi/12

06-The linear and angular velocities of a particle moving about the centre of a circle of radius r, are related by

V=w x r

V x w =r

V = r x w

W x v r

07-The angular analogue of linear displacement is called:

Angular velocity

Angular momentum

Angular displacement

Moment of force

08-Ten seconds after an electric fan is turned on, the fan rotates at 300 rev/min. Its average angular acceleration is:

30 rads^-2

3.14 rads^-2

30 revs^-2

500 revs^-2

09-In case of planets, the necessary acceleration is provided by:

Gravitational force

Frictional force

Coulomb force

Centripetal force

10-If a car moves with a uniform speed of 2 m/s in a circle of radius 0.4 m. Its angular speed is:

4 rad.s-1

5 rad.s-1

1.6 rad.s-1

2.8 rad.s-1

11-Angular speed of second's hand of a watch in rad/s is:

Pi/2

Pi/30

Pi/180

12-The shaft of a motor rotates at a constant angular speed of 360 rev/min. Angle turned through in 1 sec in radian is:

3 pi

6 pi

12 pi

13-The angular velocity of the minute hand of a clock is:

2pi/60 rads-1

2pi/3600 rads-1

Pi/24 rads-1

Pi/3600 rads-1

14-The direction of angular velocity is along

Tangent to the circle

Inward the radius

Axis of rotation

Outward of the radius

15-The force which provides the necessary centripetal force to keep the mud in circular path is called:

Cohesive force

Frictional force

Adhesive force

Gravitational force

16-A disc of radius R=20 cm is rotating about its axis with an angular velocity w =20 rad/s on a horizontal smooth surface. The linear speed of point C on the disc is:

1 m/s

2 m/s

4 m/s

4pi m/s

17-Two particles of equal masses are revolving in circular paths of radius r1 and r2 respectively with same speed. The ratio of their centripetal force is:

R2/r1

( r2/r1 )^2

� (r2/r1)

( r1/r2 )^2

18-When a body moves in a circle, the angle between its velocity v and angular velocity w is always:

360'

180'

90'

19-The average angular velocity is defined by the relation

20-If a rotating body is moving counter clockwise, direction of angular velocity will be

Along linear velocity

Along the axis of rotation

Towards the canter

Away from the center

21-A body is moving in a circle with a constant speed v. It has:

A constant velocity

A constant acceleration

A velocity of constant magnitude

An acceleration of constant magnitude

22-A body of mass m is moving in a circle of radius r with a constant speed v. The work done by the centripetal force in moving the body over half the circumference of the circle is:

Mv^2/r x 2r

Mv^2/r x pi r

Mv^2/r x r

Zero

23-A particle moves in a circle of radius 25 cm at two revolutions per second. The acceleration of the particle in m/s^2 is:

π^2

8π^2

4π^2

2π^2

24-A small sphere is attached to a cord and rotates in a vertical circle about a point O. If the average speed of the sphere is increased, the cord is most likely to break at the orientation when the mass is at the

Bottom point B

Point C

Point D

Top point A

25-For a body moving with constant speed in a horizontal circle, WOF remains constant?

Velocity

Acceleration

Centripetal force

Kinetic energy

26-The length of the second hand of a watch is 1 cm. The velocity vector of the tip of the second hand in cm per second is:

2 pi

2 pi/(12x 60)

2 pi /60

2 pi /(24 x 60)

27-The ratio of angular frequency and linear frequency is:

2 pi

1/ 2pi

Pi / 2

28-If the position vector of a particle is r=(3i + 4 j) m and its angular velocity is w=(j + 2k rad/sec then its linear velocity is (in m/s)

-(8i-6j+3k)

-(3i-6j+6k)

(3i-6j+8k)

(6i-8j+3k)

29-The angular momentum changes from 2 units to 6 units in 4s.The torque is:

1 unit

1/2 unit

3/2 unit

4 unit

30-The moment of inertia of a flywheels are 4 kgm^2. A torque of 10 Nm is applied on it. The angular acceleration produced will be:

25 rad/s^2

0.25 rad/s^2

2.5 rad/s^2

Zero

31-The mud flies off the tyre of a fast moving car in the direction:

Parallel to the moving tyre

Tangent to the moving tyre

Anti-parallel to the moving tyre

None of these

32-In uniform circular motion, the factor that remain constant is:

Linear velocity

Acceleration

Centripetal force

Speed

33-A flyingwheel gains a speed of 540 rpm in 6 s. Its angular acceleration is:

3 pi rad s-2

9pi rad s-2

6 pi rad s-2

12 pi rad s-2

34-One end of the string of length 1.0 m is tied to a body of mass 0.5 kg. It is whirled in a vertical circle as shown in figure below. If the angular frequency of the body is 4 rad s-1, what is the tension in the string when the body is at the topmost point A? (Take g 10ms-2.)

13N

15N

18N

35-A particle is moving with constant speed by keeping itself at constant distance from a fixed point in a given plane. Its motion is:

Circular motion

Uniform circular motion

Uniform circular motion with fixed axis of rotation

Uniform circular motion with axis of rotation

36-For a particle in uniform circular motion, the relation a=r@ of accelerations hold. The acceleration 'a' is:

Its centripetal acceleration

Its radial acceleration

Its tangential acceleration

First 2 options

37-A stone of mass 250 g is tied to the end of a string of length 1.0. It is whirled in a horizontal circle with a frequency of 30 rev/min. What is the tension in a string?

π^2 /4

π^2

π^2/2

2π^2

38-A body moving in circular path with a constant speed has a:

Constant velocity

Constant acceleration

Constant kinetic energy

Constant displacement

39-A point on the rim of a wheel 4 m in diameter has a velocity of 1600 cm s-1. The angular velocity of the wheel is:

2 rad s-1

6 rad s-1

4 rad s-1

8 rad s-1

40-A stone of mass m tied to a string of length l is rotated in a circle with the other end of the string as the centre. The speed of the stone is v. If the string breaks, the stone will move:

Towards the centre of the circle

Along the tangent

Away from centre of cirrcle

All of these

41-A flywheel gains a speed of 540 rpm in 6 s. Its angular acceleration is:

3 π rad s-2

9 π rad s-2

6 π rad s-2

12 π rad s-2

42-If the distance between the earth and the sun is reducing to one fourth, then the number of days in one year approximately?

183

129

365

43-The ratio of angular frequency and linear frequency is:

2π

1/π

π/2

44-If a body is moving in circular path with constant speed, then the

Velocity and acceleration are perpendicular to each other

Velocity and acceleration are parallel to each other

Velocity and acceleration are anti-parallel

Both have zero magnitude

45-The earth (m=6 x 10^24 kg) revolves around the sun with an angular velocity of 2 x 10^-7 rad/s in a circular path of radius 1.5 x 10^8 km. The force exerted by Sun on earth is:

6 x 10^19 N

18 x 10^25 N

36 x 10^21 N

27 x 10^39 N

46-A body is moving in a circular path with constant speed. The magnitude of tangential and centripetal acceleration are respectively:

Rv^2, 0

0, 0

0, v^2/r

V^2/r, v^2/r

47-A rigid body is rotating about on axis of rotation as shown. The ratio of angular accelerations of point A to that of B.

1 : 1

2 : 3

3 : 2

1 : 6

48-A body rotates with uniform speed in a circle of radius r and takes time T to complete one revolution. What are the magnitudes of the angular velocity w, the linear velocity v and acceleration a respectively?

1/T, 4πr/T, 2πr/T^2

2π/t, 2πr/T, 2πr/T^2

2π/T, 2πr/T, 4π^2 r/T^2

2π/T, 4πr/T, 4π^2r/T^2,

49-A wheel rotates about an axis passing through the centre and perpendicular to the plane with slowly increasing angular speed. Thus it has:

Radial velocity and radial acceleration

Tangential velocity and radial acceleration

Tangential velocity and tangential acceleration

Tangential velocity but acceleration having both components

50. 2πr subtends an angle of:

1 radian

2 radian

4 radian

2π radian

51-A particle revolves round a circular path with a constant speed. The acceleration of the particle is:

Along the circumference of the circle

Along the tangent

Along the radius

Zero

52-For a particle moving in uniform circular motion:

Velocity is transverse and acceleration is radial

Both velocity and acceleration and acceleration are radial

Velocity is radial and acceleration is transverse

Both velocity and acceleration are transverse

53-The force which can do no work on the body on which it acts:

Frictional force

Gravitational force

Elastic force

Centripetal force

54-The acceleration that is only due to change in direction of motion only is:

Linear

Tangential

Angular

Centripetal

55-The phase between linear velocity and angular velocity of a rotating body is:

π/4

2π

π/2

56-A body is moving in a circle of radius (r) with a variable speed, the acceleration of the body is:

Centripetal acceleration

Angular acceleration

Tangential acceleration

All of above

57-For a particle in a non-uniform accelerated circular motion:

Velocity is radial and acceleration is transverse only

Velocity is transverse and acceleration has both radial and transverse components

Velocity is transverse and acceleration is radial only

Velocity is radial and acceleration has both radial and transverse components

58-A body crosses the top most point of a vertical circle with critical speed. Its centripetal acceleration, when the string is horizontal will be:

59-For a particle in circular motion, the centripetal acceleration is:

May be more or less than its tangential acceleration

Equal to its tangential acceleration a

More than its tangential acceleration

Less than its tangential acceleration

60-A cyclist turns around a curve at 15 miles/hour. If he turns at at double the speed, the tendency to overturn is:

Quadrupled

Unchanged

Halved

Doubled

PHYSICS-Rotational and Circular Motion (SMART INSTITUTE)

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