A uniform rod AB of mass m and length L rotates about a fixed vertical axis making a constant angle `theta` with it as shown in figure. The rod is rotated about this axis, so that point B the free end of the rod moves with a uniform speed `V` in the horizontal plane then the angular momentum of the rod about the axis is:

Options

A. `(1)/(2)mVLcostheta`
B. `(1)/(3)mVLsintheta`
C. `mVLsincostheta`
D. zero

Answer

B

Explanation

Moment of inertial of rod about the axis
`I=(1)/(3)mL^(2)sin^(2)theta`
`L=Iomega=(1)/(3)mL^(2)sin^(2)theta(V)/(Lsintheta)=(1)/(3)mVLsintheta`