Thank you for reporting, we will resolve it shortly
Q.
A proton, a deuteron and an $\alpha$-particle with same kinetic energy enter into a uniform magnetic field at right angle to magnetic field. The ratio of the radii of their respective circular paths is :
$R =\frac{\sqrt{2 km }}{ qB } \propto \frac{\sqrt{ m }}{ q }$
$\frac{\sqrt{ m }}{ e }: \frac{\sqrt{2 m }}{ e }: \frac{\sqrt{4 m }}{2 e }$
$1: \sqrt{2}: 1$