A charged particle is moving in a circular orbit of radius 6 cm with a uniform speed of `3 xxx 10^(6)` m/s under the action of a uniform magnetic field `2 xx 10^(-4) wb//m^(2)` at right angles to the plane of the orbit. The charge to mass ratio of the particle is

Options

A. `5 xx 10^(9)` C /kg
B. `2.5 xx 10^(11)` C/kg
C. `5 xx 10^(11)` C /kg
D. `5 xx 10^(12)` C/kg

Answer

B

Explanation

r = 0.06 m , v `= 3 xx 10^(6) , B = 2 xx 10^(-4)` T
`r= (mv)/(qB) implies 0.06 = (3 xx 10^(6))/((q//m) xx 2 xx 10^(-4))`
`implies (q)/(m) = (3 xx 10^(6))/(2 xx 10^(4) xx 6 xx 10^(-2)) = 2.5 xx 10^(11)` C/kg.