For photoelectric effect which of the following statements are true. (I) The kinetic energies of the photoelectrons do not depend on the frequency of light. (II) Photoelectric effect will always occur for highly intense light. (III) The maximum kinetic energy of photoelectron does not depend upon the intensity of the light. (IV) The escaping electron's kinetic energy is larger for larger frequency.

Which of the following statements is not true?

The light emitted in the transition $n=3$ to $n=2$, (where $n$ is the principal quantum number of the state) in hydrogen is called $\mathrm{H}_\alpha$-light. Find the maximum work function that a metal can have, so that $\mathrm{H}_\alpha$-light can emit photoelectrons from it.

A light of wavelength 310 nm is used in a photoelectric experiment. The metal electrode of work function of 2.5 eV is used in the experiment. The stopping potential for the photoelectrons will be (assume, $h c=1240 \mathrm{eV}-\mathrm{nm}$ )