A beam of ions with velocity ` 2xx 10^(5) ` m/s enters normally into a uniform magnetic field of ` 4 xx 10^(-2)` T. if the specific charge to the ions is ` 5xx 10^(7) ` C/kg, the radius of the circular path described will be

Options

A. 0.10 m
B. 0.16 m
C. 0.20 m
D. 0.25 m

Answer

A

Explanation

Radius of the cicrlar path is given by
` R = (mv)/(qB) = v/((q/m)(B))`
`= (2 xx 10^(5)m//s)/((5 xx 10^(7) Ckg^(-1))(4 xx 10^(-2)T))`
= 0.1 m