
$\mathrm{E}=\frac{\mathrm{u}^{2} \mathrm{m}}{\mathrm{qR}}$
$\frac{1}{2} \mathrm{mu}^{2}=\mathrm{KE}$
$\mathrm{E}=\frac{\mathrm{m}}{\mathrm{q} \mathrm{R}} \frac{2 \mathrm{KE}}{\mathrm{m}}=\frac{2(\mathrm{KE})}{\mathrm{qR}}$



Reason : Capacity of the capacitor does not depend upon the nature of the material.

