A proton and an alpha particle are accelerated through the same potential difference. The ratio of their kinetic energies is
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → \( \displaystyle\frac{K_p}{K_\alpha} = \frac{1}{2} \)
A charge q accelerated from rest through a potential difference V gains kinetic energy equal to the work done by the field, qV. This does not depend on the mass. The proton has charge e and the alpha particle has charge 2e.
\( K = qV \)
\( \displaystyle \frac{K_p}{K_\alpha} = \frac{eV}{2eV} \)
\( \displaystyle \frac{K_p}{K_\alpha} = \frac{1}{2} \)