If the intensity of incident radiation on metal is doubled, the kinetic energy of electrons emitted would be

unaffected

The correct answer is Option (3) → unaffected

Explanation:

According to Einstein’s photoelectric equation:

$ K_{\text{max}} = h\nu - \phi $

where $K_{\text{max}}$ is the maximum kinetic energy, $h$ is Planck’s constant, $\nu$ is the frequency of incident light, and $\phi$ is the work function of the metal.

The kinetic energy of emitted electrons depends only on the frequency of the incident radiation, not on its intensity.

Hence, when the intensity is doubled, the number of emitted electrons increases, but their kinetic energy remains the same.

Therefore, the kinetic energy is unaffected.