NEET Physics Systems of Particles and Rotational Motion MCQs Set B

a) 25 rad/s²

b) 25 m/s²

c) 0.25 rad/s²

d) 5 m/s²

Answer: 25 rad/s²

Question: A solid sphere rolls down two different inclined planes of same height, but of different inclinations. In both cases

a) speed will be same, but time of descent will be different

b) speed will be different, but time of descent will be same

c) speed and time of descent both are different

d) speed and time of descent will be same

Answer: speed will be same, but time of descent will be different

Question: Assertion : Radius of gyration of body is a constant quantity.
Reason : The radius of gyration of a body about an axis of rotation may be defined as the root mean square distance of the particle from the axis of rotation.

a) Assertion is incorrect, reason is correct

b) Assertion is incorrect, reason is correct

c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

d) Assertion is correct, reason is correct; reason is a correct explanation for assertion.

Answer:  Assertion is incorrect, reason is correct

Question:

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d)

Answer:

Question:   A thin but rigid semicircular wire frame of radius r is hinged at O and can rotate in its own vertical plane. A smooth peg P starts from O and moves horizontally with constant speed v₀, lifting the frame upward as shown in figure.

a)

b)

c)

d)

Answer:

Question:  A solid sphere is in rolling motion. In rolling motion a body possesses translational kinetic energy (K_t) as well as rotational kinetic energy (K_r) simultaneously. The ratio Kt : (K_t + K_r) for the sphere is

a) 5 : 7

b) 2 : 5

c) 10 : 7

d) 7 : 10

Answer:  5 : 7

Question:

a)

b)

c)

d)

Answer:

Question: Assertion : When a sphere is rolls on a horizontal table it slows down and eventually stops.
Reason : When the sphere rolls on the table, both the sphere and the surface deform near the contact. As a result, the normal force does not pass through the centre and provide an angular declaration.

a) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

b) Assertion is correct, reason is incorrect

c) Assertion is incorrect, reason is correct.

d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: Assertion is correct, reason is correct; reason is not a correct explanation for assertion

Question:  Seven identical circular planar disks, each of mass M and radius R are welded symmetrically as shown. The moment of inertia of the arrangement about the axis normal to the plane and passing through the point P is:

a)

b)

c)

d)

Answer:

Question:  A particle is moving with a uniform speed in a circular orbit of radius R in a central force inversely proportional to the n^th power of R. If the period of rotation of the particle is T, then:

a)

b)

c)

d)

Answer:

Question:  A hoop rolls down an inclined plane. The fraction of its total kinetic energy that is associated with rotational motion is

a) 1 : 2

b) 1 : 3

c) 1 : 4

d) 2 : 3

Answer:  1 : 2

 More Questions.....................................

Question:

a)

b)

c)

d)

Answer:

Question:   Three identical rods are hinged at point A as shown. The angle made by rod AB with vertical is

a)

b)

c)

d)

Answer:

Question:

a) The centre of mass moves towards right

b) The centre of mass remains stationary

c) The net force about the centre of mass of the spool is zero

d) The centre of mass moves towards left

Answer: The centre of mass moves towards right

Question:  Velocity of the centre of a small cylinder is v. There is no slipping anywhere. The angular velocity of the centre of the larger cylinder is

a) v

b) 2v

c) None of these

d) 3v

Answer: v

Question:  A ring of mass M and radius R is rotating about its axis with angular velocity w. Two identical bodies each of mass m are now gently attached at the two ends of a diameter of the ring. Because of this, the kinetic energy loss will be :

a)

b)

c)

d)

Answer:

Question:  A uniform solid cube of mass M has edge length a. The moment of inertia of the cube about its face diagonal will be

a)

b)

c)

d)

Answer:

Question:  A uniform thin rod is bent in the form of closed loop ABCDEFA as shown in the figure. The ratio of moment of inertia of the loop about x-axis to that about y-axis is

a) < 1

b) > 1

c) = 1

d) = 1/2

Answer: < 1

Question:  A shaft is rotating at a speed of 4000 revolutions per minute. If the power expended in driving the shaft is 12 kW, the magnitude of the driving torque is :

a)

b)

c) 90 Nm

d) 180 Nm

Answer:

Question:

a) 60 units

b) zero

c) 7.5 units

d) 8.5 units

Answer:  60 units

Question:

a) K/ 2

b) K

c) K/ 4

d) 2 K

Answer:  K/ 2

Question:

a)

b)

c)

d)

Answer:

Question:   A block of mass m is attached to a pulley disc of equal mass m and radius r by means of slack string as shown. The pulley is hinged about its centre on a horizontal table and the block is projected with an initial velocity of 5 m/s. Its velocity when the string becomes tight will be

a) 10/3 m/s

b) 5/3 m/s

c) 2.5 m/s

d) 3 m/s

Answer:  10/3 m/s

Question:

a)

b)

c)

d) None of these

Answer:

Question:

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d) zero

Answer:

Question:

a) 7.6 cm

b) 4.3 cm

c) 12.6 cm

d) 15.3 cm

Answer:  7.6 cm

Question:

a)

b)

c)

d) None of these

Answer:

Question:

a)

b)

c)

d)

Answer: