Angular Momentum Questions

Angular momentum is described as the property of any rotating object given by moment of inertia times angular velocity.

Angular momentum is a vector quantity and is denoted by vector L.

It is measured using SI base units: Kg.m2.s-1. The dimensional formula is: [M][L]2[T]-1

Angular momentum of a point object is given by:

\(\begin{array}{l}\vec{L}=r\times \vec{p}\end{array} \)

Angular momentum of an extended object is given by:

\(\begin{array}{l}\vec{L}=I\times \vec{\omega }\end{array} \)

The angular momentum is classified into:

  • The spin angular momentum
  • The orbital angular momentum

Read more: Angular Momentum

Important Angular Momentum Questions with Answers

Momentum is the product of mass and _____.

  1. Distance
  2. Displacement
  3. Velocity
  4. Acceleration

Answer: c) Velocity

Explanation: Momentum is defined as the product of mass and velocity.

2. Earth revolving around the sun is an example of ______.

  1. Angular momentum of a point object
  2. Angular momentum of an extended object

Answer: a) Angular momentum of a point object

Explanation: Since the object is accelerating around a fixed point, it is an example of the angular momentum of a point object.

3. Angular momentum is represented by ______.

  1. A
  2. M
  3. L
  4. P

Answer: c) L

Explanation: Angular momentum is represented by, L

4. Angular momentum is a _____ quantity.

  1. Scalar
  2. Vector
  3. Dimensionless
  4. None of the options

Answer: b) Vector

Explanation: Angular momentum is a vector quantity which gives both magnitude and direction.

5. Which of the following devices uses the principle of angular momentum?

  1. Voltameter
  2. Stethoscope
  3. Gyroscope
  4. Otoscope

Answer: c) Gyroscope

Explanation: A Gyroscope is a device which operates on the principle of angular momentum.

6. The direction of angular momentum is given by the _____.

  1. Right-hand rule
  2. Left-hand rule

Answer: a) Right-hand rule

Explanation: Right-hand rule gives the direction of angular momentum.

7. Angular momentum of an extended object is given by the formula _____.

  1. \(\begin{array}{l}\vec{L}=I\times + \vec{\omega }\end{array} \)
  2. \(\begin{array}{l}\vec{L}=I\times – \vec{\omega }\end{array} \)
  3. \(\begin{array}{l}\vec{L}=2(I\times + \vec{\omega })\end{array} \)
  4. \(\begin{array}{l}\vec{L}=I\times \vec{\omega }\end{array} \)

Answer: d)

\(\begin{array}{l}\vec{L}=I\times \vec{\omega }\end{array} \)

Explanation: Angular momentum of an extended object is given by the formula

\(\begin{array}{l}\vec{L}=I\times \vec{\omega }\end{array} \)

8. Choose YES or NO: Does angular momentum specify the direction?

  1. YES
  2. NO

Answer: a) YES

Explanation: Angular momentum is a vector quantity since it has both magnitude and direction.

9. What happens to angular velocity when the moment of inertia of an isolated system is halved?

  1. It becomes zero
  2. It doubles
  3. Ii is halved
  4. Remains same

Answer: b) It doubles

Explanation: The angular velocity doubles when the moment of inertia of an isolated system is halved.

10. What is the dimensional formula for angular momentum?

The dimensional formula for angular momentum is ML2T-1.

Watch the video below to know more about angular momentum.

Practice Questions

  1. Define angular momentum.
  2. The rotation of the earth about its axis is an example of which angular momentum?
  3. How is the angular momentum classified?
  4. Define the orbital angular momentum.
  5. What is the formula to find the momentum?

Related links

Conservation of angular momentum

Angular momentum formula

Electrical energy and Power

Angular Momentum about fixed axis

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