Question

A proton , a deutron and `alpha )`- particle having the same kinetic energy are moving in circular trajectories in a constant magnetic field . If ` r_(p), r_(d) , and r_(alpha)` denote respectively the radii of the trajectories of these particles , then
A. ` r_(alpha) = r_(p)lt r_(d)`
B. ` r_(alpha) gt r_(p) gt r_(p)`
C. ` r_(alpha) = r_(d) gt r_(p)`
D. ` r_(p) = r_(d) = r_(alpha)`

Answer 1

Correct Answer - A
Key concept : ` r prop (sqrt(m))/(q)`
:. ` r_(p) :r_(d): r _(alpha) = ( sqrt (1))/(1) : ( sqrt(2))/(1) : (sqrt (4))/(1) = 1 : sqrt (2) : 1 `
rArr `rArr_(alpha) = r_(p) lt r_(d) `