The threshold frequency of potassium is $3 \times 10^{14} \ Hz$. The work function is ...... .

Photons of energy $10 eV$ are incident on a photosensitive surface of threshold frequency $2 \times 10^{15} Hz$. The kinetic energy in $eV$ of the photoelectrons emitted is [Planck's constant $h = 6.63 \times 10^{-34} Js$]. (in $eV$)

The threshold frequency for a metallic surface corresponds to an energy of $6.2 \ eV$ and the stopping potential for a radiation incident on this surface is $5 \ V$. The incident radiation lies in:

The figure showing the correct relationship between the stopping potential $V_0$ and the frequency $\nu$ of light for potassium and tungsten is

Light of frequency $4v_0$ is incident on a metal surface with a threshold frequency $v_0$. The maximum kinetic energy of the emitted photoelectrons is:

Einstein's photoelectric equation states that ${E_k} = h\nu - \phi$. In this equation,${E_k}$ refers to: