(c) Kinetic energy of the ions,
$\frac{1}{2}mv^{2} = \frac{q^{2}B^{2}R^{2}}{2m}$
For $\alpha$ particle, the charge is two times that of the proton but mass is 4 times that of the proton
Therefore, compared to proton’ kinetic energy, for the same conditions in the cyclotron, energy of alpha particle is $E$