A particle performing uniform circular motion has  angular momentum L . its angular frequency is doubled and its kinetic energy halved, then the new angular momentum is

Option 1)

L/4

Option 2)

2L

Option 3)

4L

Option 4)

L/2

Answers (1)

As we learnt in

Rotational angular momentum -

\vec{L}= I\vec{w}

 

- wherein

I = Moment of inertia about fixed axis of rotation

w = angular velocity of rotation

 

 

 We know that L=I\omega

K.E_{not}=\frac{1}{2}I \omega^{2} 

\frac{L}{K}_{not}=\frac{2I\omega}{I\omega^{2}}=>\frac{L}{K}=\frac{2}{\omega}=>L=\frac{2K}{\omega}

\therefore \frac{L_{1}}{L_{2}}=\frac{K_{1}}{K_{2}}\times \frac{\omega_{2}}{\omega_{1}}=2\times 2=4

    \frac{L_{1}}{L_{2}}=4=>L_{2}=\frac{L_{1}}{4} = \frac{L}{4}


Option 1)

L/4

This is the correct option.

Option 2)

2L

This is an incorrect option.

Option 3)

4L

This is an incorrect option.

Option 4)

L/2

This is an incorrect option.

Preparation Products

JEE Main Rank Booster 2021

This course will help student to be better prepared and study in the right direction for JEE Main..

₹ 13999/- ₹ 9999/-
Buy Now
Knockout JEE Main April 2021 (Subscription)

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 6999/- ₹ 5/-
Buy Now
Knockout JEE Main April 2021

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 22999/- ₹ 14999/-
Buy Now
Knockout JEE Main April 2022

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 34999/- ₹ 24999/-
Buy Now
Knockout JEE Main January 2022

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 34999/- ₹ 24999/-
Buy Now
Exams
Articles
Questions