Question

A charged particle moves in a uniform magnetic field perpendicular to it, with a radius of curvature 4 cm. On passing through a metallic sheet it loses half of its kinetic energy. Then, the radius of curvature of the particle is
A. `2 cm`
B. `4 cm`
C. `8 cm`
D. `2sqrt2 cm`

Answer 1

Correct Answer - d
`R=(mv)/(qB) =m/(qB) sqrt((2(KE))/m)=(sqrt(2m))/(qB)sqrt(KE)`
`implies (R_1)/(R_2) (sqrt(KE))/(sqrt(KE//2)) implies R_2=(R_1)/(sqrt2)=4/(sqrt2)=2sqrt2 cm`