The momentum of a photon with energy $20\, eV$ is
$10.0 \times {10^{ - 27}}\,\frac{{kg \times m}}{s}$
$10.95 \times {10^{ - 27}}\,\frac{{kg \times m}}{s}$
$10.66 \times {10^{ - 27}}\,\frac{{kg \times m}}{s}$
$10.2 \times {10^{ - 27}}\,\frac{{kg \times m}}{s}$
The energy of a photon of light with wavelength $5000\,\mathop A\limits^o $ is approximately $2.5\, eV$. This way the energy of an $X-$ ray photon with wavelength $1\,\mathop A\limits^o $ would be
Energy of photon whose frequency is ${10^{12}}MHz,$ will be
Photoelectric effect was successfully explained first by
The work function of a photoelectric material is $3.3 eV$. The threshold frequency will be equal to