An electron, a proton, a deuteron and an alpha particle, each having the same speed are in a region of constant magnetic field perpendicular to the direction of the velocities of the particles. The radius of the circular orbits of these particles are respectively `R_(e), R_(p), R_(d)` and `R_(alpha)` It follows that

Options

A. `R_(e) = R_(p)`
B. `R_(p) = R_(d)`
C. `R_(d) = R_(a)`
D. `R_(p) = R_(a)`

Answer

C

Explanation

`r = (mv)/(qB) implies r prop (m)/(q)`
`R_(e) lt R_(p)` and `R_(d) and R_(a)`