A particle having a charge of `10.0muC` and mass `1mug` moves in a circle of radius 10 cm under the influence of a magnetic field of induction 0.1T. When the particle is at a point P, a uniform electric field is switched on so that the particle starts moving along the tangent with a uniform velocity. The electric field is

Options

A. 0.1 V/m
B. 1.0 V/m
C. 10.0 V/m
D. 100 V/m

Answer

C

Explanation

`qE = qvB implies E = vB`
`r = (mv)/(qB) implies v = (q Br)/(m)`
`therefore E = (qB^(2) r)/(m) = 10 V//m`