A particle having mass `m`, charge `q` enters a cylindrical region having uniform magnetic field `B` in the inward direction as shown. If the particle is deviated by `60^(@)` as it emerges out of the field then what is the time spent by it in the field?

Options

A. `(2pim)/(qB)`
B. `(2pim)/(3qB)`
C. `(pim)/(3qB)`
D. It depends on the speed of particle.

Answer

C

Explanation

Angle rotated in magnetic field = `60^(@)`

So time taken should be `(1)/(6)th` of time period.
` t=(T)/(6)=(1)/(6)((2pim)/(qB))=(pim)/(3qB)`