# Topic: UNIT V: Motion of System of Particles and Rigid Bodies (Test 1)

Topic: UNIT V: Motion of System of Particles and Rigid Bodies
Q.1
The center of mass of a system of particles does not depend upon,
A. position of particles
B. relative distance between particles
C. masses of particles
D. force acting on particle
Explaination / Solution:
No Explaination.

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Q.2
A couple produces,
A. pure rotation
B. pure translation
C. rotation and translation
D. no motion
Explaination / Solution:
No Explaination.

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Q.3
A particle is moving with a constant velocity along a line parallel to positive X-axis. The magnitude of its angular momentum with respect to the origin is,
A. zero
B. increasing with x
C. decreasing with x
D. remaining constant
Explaination / Solution:
No Explaination.

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Q.4
A rope is wound around a hollow cylinder of mass 3 kg and radius 40 cm. What is the angular acceleration of the cylinder if the rope is pulled with a force 30 N?
C. 5 m s–2
D. 25 m s–2.
Explaination / Solution:
No Explaination.

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Q.5
A closed cylindrical container is partially filled with water. As the container rotates in a horizontal plane about a perpendicular bisector, its moment of inertia,
A. increases
B. decreases
C. remains constant
D. depends on direction of rotation
Explaination / Solution:
No Explaination.

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Q.6
A rigid body rotates with an angular momentum L. If its kinetic energy is halved, the angular momentum becomes,
A. L
B. L/2
C. 2L
D. L/ 2
Explaination / Solution:
No Explaination.

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Q.7
A particle undergoes uniform circular motion. The angular momentum of the particle remain conserved about,
A. the center point of the circle
B. the point on the circumference of the circle
C. any point inside the circle
D. any point outside the circle
Explaination / Solution:
No Explaination.

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Q.8
When a mass is rotating in a plane about a fixed point, its angular momentum is directed along,
A. a line perpendicular to the plane of rotation
B. the line making an angle of 45° to the plane of rotation
D. tangent to the path
Explaination / Solution:
No Explaination.

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Q.9
Two discs of same moment of inertia rotating about their regular axis passing through center and perpendicular to the plane of disc with angular velocities ω1 and ω2. They are brought in to contact face to face coinciding the axis of rotation. The expression for loss of energy during this process is,
A. 1/4 I (ω1- ω2)2
B. I (ω1- ω2)2
C. 1/8 I (ω1- ω2)2
D. 1/2 I (ω1- ω2)2
Explaination / Solution:
No Explaination.

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Q.10
A disc of moment of inertia Ia is rotating in a horizontal plane about its symmetry axis with a constant angular speed ω. Another discinitially at rest of moment of inertia Ib is dropped coaxially on to the rotating disc. Then, both the discs rotate with same constant angular speed. The loss of kinetic energy due to friction in this process is,
A. B. C. D. 