Three discs each of mass M and radius R are placed in contact with each other as shown in figure here. Then the MI of the system about an axis XX' is

Options

A. `(11)/(2)MR^(2)`
B. `(11)/(4)MR^(2)`
C. `(7)/(2)MR^(2)`
D. `(7)/(4)MR^(2)`

Answer

B

Explanation

`I=2I_(t)+I_(d)=2xx(5)/(4)MR^(2)+(MR^(2))/(4)`
`= (11)/(4)MR^(2)`.