Two rigid bodies A and B rotate with rotational kinetic energies `E_(A)` and `E_(B)` respectively. The moments of inertia of A and B about the axis of rotation are `I_(A)` and `I_(B)` respectively. If `I_(A) = I_(B)//4` and E_(A)= 100 E_(B), the ratio of angular momentum (L_(A)) of A to the angular momentum (L_(B)) of B is

Options

A. 25
B. `5//4`
C. 5
D. `1//4`

Answer

C

Explanation

`(K_(A))/(K_(B))= (L_(A)^(2))/(2I_(A)) xx (2I_(B))/(L_(B)^(2))`
`rArr 100= (L_(A)^(2))/(L_(B)^(2)) xx 4 rArr (L_(A))/(L_(B)) = 5`