Correct Answer - B
We know that angular momentum of the body is given by
`L=I omegaor L=Ixx(2pi)/(T)or L prop (1)/(T)rArr (L_(1))/(L_(2))=(T_(2))/(T_(1))`
`rArr(L)/(L_(2))=(2T)/(T)" "(As, T_(2)=2T and L_(2)=L)`
So, `L_(2)=(L)/(2)`. Thus, on doubling the time period, angular momentum of body becomes half.