A uniform magnetic field of induction `B` is confined to a cylindrical region of radius `R`. The magnetic field is increasing at a constant rate of `dB//dt` (tesla`//` second). A charge `e` of mass `m`, placed at the point `P` on the periphery of the fixed experiences an acceleration :

Options

A. `(1)/(2)(eR)/(m)(dB)/(dt)` toward left
B. `(1)/(2)(eR)/(m)(dB)/(dt)` toward right
C. `(eR)/(m)(dB)/(dt)` toward left
D. zero

Answer

A

Explanation

(a) Induced electric field at point `P`:
`E = (R )/(2)(dB)/(dt)` towards right
acceleration of electron: `a = (eE)/(m) = (eR)/(2m)(dB)/(dt)` towards left