A particle moves in a circle of diamater 1.0 cm under the action of magnetic field of 0.40 T, An electric field of `200 V m^(-1)` makes the path straight. Find the charges/mass ration of the particle.

Options

A. `2.5 xx 10^(5) C//kg`
B. `2.0 xx 10^(5) C//kg`
C. `2.5 xx 10^(6) C//kg`
D. `3.0 xx 10^(5) C//kg`

Answer

A

Explanation

`F_(m) = F_(e)`
`qvB = qE`
`v xx 0.4 = 200 rArr v = 500 m//sec`
`R = (mv)/(Bq)`
`(q)/(m) = (v)/(BR) = (500)/(0.4 xx ((0.01)/(2))) = 2.5 xx 10^(6) C//kg`