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_(alpha)`
D. `R_(p)=R_(alpha)`

Answer

C

Explanation

By using `r=(mv)/(qB)=(v)/((q)/(m)B)impliesrprop(1)/(q//m)P1`
`:' ((q)/(m))_(e^(-))gt((q)/(m))_(p^(+))gt{((q)/(m))_(d)=((q)/(m))_(alpha)}`
` R_(d)=R_(alpha)`