EWT | Academic Question

Questions
Question (1)
QN0038697
  1. Three identical spherical shells, each of mass  and radius  are placed as shown in figure. Consider an axis  ' which is touching to two shells and passing through diameter of third shell. Moment of inertia of the system consisting of these three spherical shells about  axis is

A black and white drawing of a tree

Description automatically generated          

  • (A)

  • (B)

  • (C)

  • (D)

Correct Answer: C
Explanation:

Moment of inertia of shell 1 along diameter

Moment of inertia of shell . i of shell 3

So,  of the system along

or,

Link:
Report Error
Question (2)
QN0038698

A rod of weight  is supported by two parallel knife edges  and  and is in equilibrium in a horizontal position. The knives are at a distance  from each other. The centre of mass of the rod is at distance  from . The normal reaction on  is           

  • (A)

  • (B)

  • (C)

  • (D)

Correct Answer: C
Explanation:

By torque balancing about

Link:
Report Error
Question (3)
QN0038699
  1. A mass  moves in a circle on a smooth horizontal plane with velocity  at a radius . The mass is attached to string which passes through a smooth hole in the plane as shown.

The tension in the string is increased gradually and finally  moves in a circle of radius . The final value of the kinetic energy is                                                                
 

  • (A)

  • (B)

  • (C)

  • (D)

Correct Answer: B
Explanation:

Applying angular momentum conservation

Therefore, new

Link:
Report Error
Question (4)
QN0038700

A force  is acting at a point . The value of  for which angular momentum about origin is conserved is 

  • (A)

    2

  • (B)

    zero

  • (C)

    1

  • (D)

    -1

Correct Answer: A
Explanation:

Given: Radius of disc,

angular acceleration ; time

Particle at periphery (assume) will have both radial (one)

and tangential acceleration

From equation,

Net acceleration,

Link:
Report Error
Question (5)
QN0038701

A uniform circular disc of radius  at rest is free to turn about an axis which is perpendicular to its plane and passes through its centre. It is subjected to a torque which produces a constant angular acceleration of . Its net acceleration in  at the end of  is approximately : 

  • (A)

    8.0

  • (B)

    7.0

  • (C)

    6.0

  • (D)

    3.0

Correct Answer: B
Explanation:

Moment of inertia of complete disc about point '  '.

Mass of removed disc

(Mass  area)

Moment of inertia of removed disc about point '  '.

(about same perpendicular axis)

Therefore the moment of inertia of the remaining part of the disc about a perpendicular axis passing through the centre,

Link:
Report Error
Question (6)
QN0038702

From a disc of radius  and mass , a circular hole of diameter , whose rim passes through the centre is cut. What is the moment of inertia of the remaining part of the disc about a perpendicular axis, passing through the centre? 

  • (A)

  • (B)

  • (C)

  • (D)

Correct Answer: D
Explanation:

Centre of mass may or may not coincide with centre of gravity. Net torque of gravitational pull is zero about centre of mass.

Mechanical advantage, M. A.

Link:
Report Error
Question (7)
QN0038703
  1. Which of the following statements are correct? 

(A) Centre of mass of a body always coincides with the centre of gravity of the body

(B) Centre of mass of a body is the point at which the total gravitational torque on the body is zero

(C) A couple on a body produce both translational and rotation motion in a body

(D) Mechanical advantage greater than one means that small effort can be used to lift a large load

  • (A)

    (A) and (B)

  • (B)

    (B) and (C)

  • (C)

    (C) and (D)

  • (D)

    (B) and (D)

Correct Answer: A
Explanation:

If M.A.  Load  Effort
16. (a) Here,

Loss in K.E.

Link:
Report Error
Question (8)
QN0038704

Two discs of same moment of inertia rotating about their regular axis passing through centre and perpendicular to the plane of disc with angular velocities  and . They are brought into contact face to face coinciding the axis of rotation. The expression for loss of energy during this process is: 

  • (A)

     

  • (B)

  • (C)

  • (D)

Correct Answer: B
Explanation:

Given, mass of cylinder

?

As we know, torque

.

or,

Link:
Report Error
Question (9)
QN0038705

A rope is wound around a hollow cylinder of mass  and radius . What is the angular acceleration of the cylinder if the rope is pulled with a force of  ?

  • (A)

  • (B)

  • (C)

  • (D)

Correct Answer: A
Explanation:

Link:
Report Error
Question (10)
QN0038706

A solid cylinder of mass  and radius  is rotating about its axis at the rate of . The torque required to stop after  revolutions is :       

  • (A)

  • (B)

  • (C)

  • (D)

Correct Answer: B
Explanation:

Given : Force,  N

Position vector,

Torque,

Link:
Report Error
Excel With Tutors

Learn At Your Own Pace... Because, Everyone's Pace of Learning is Different...

ExcelWithTutors

A unit of Innovexcel Edu Solution LLP.

SWIFT, RELIABLE & CONVENIENT..


Social Media

Corporate Office :
Bharat Impact Building, C-26, Sector - 59, Noida, Uttar Pradesh - 201301, India

Excel With Tutors : A Perfect Tutoring Platform & Repository of Learning Materials. Matches the Best Tutor as Per Your Requirement.


© 2025 | ©Innovexcel Edu Solution LLP. All Rights Reserved.

Technology Partner: Indev Consultancy Pvt Ltd

Find a Tutor Join as Tutor