Tag: photons and photoelectric effect

An electron of stationary hydrogen atom passes from the fifth energy level to the ground level. The velocity that the atom acquired as a result of photon emission will be

Violet light is falling on a photosensitive material causing ejection of photoelectrons with maximum kinetic energy of $1$ eV. Red light falling on metal will cause emission of photoelectrons with maximum kinetic energy (approximately) equal to

When an electron de-exited back from ${\left( {n + 1} \right)^{th}}$ state to ${n^{th}}$ state in a hydrogen like atoms, wavelength of radiations emitted is ${\lambda _1}\left( {n >  > 1} \right)$. In the same atom de-broglies wavelength associated with an electron in $nth$ state is ${\lambda _2}$. Then $\frac{{{\lambda _1}}}{{{\lambda _2}}}$ is proportional to 

Approximately, the temperature corresponding to $1 eV$ translational kinetic energy of molecule is

The work function of a metal is $3.3\times{  10}^{  -19}J$. The maximum wavelength of the photons required to eject electron from the metal is:

A metal plate of area $1\times { 10 }^{ -4 }{ m }^{ 2 }$ is  illuminated by a radiation of intensity 16 m $W/{ m }^{ 2 }.$ The work function of the metal is 5 eV. The energy of the incident photons is 10 eV and only 10% of it produces photo electrons. The number of emitted photo electrons per second and their maximum energy, respectively, will be :
$\left[ { 1eV=1.6\times 10^{ 19 }J } \right] $

The energy of a hydrogen-like atom (or ion ) in its ground state is - 122.4 eV. It may be :

When radiations of wavelength 3000 are incident on a photosensitive surface, the kinetic energy of electrons is 2.5 eV. The stopping potential for 1500 will he,

A photon of energy 12.75 eV is completely absorbed by a hydrogen atom initially in the ground state. The quantum number of the excited state is:

If an $\alpha$-particle is accelerated with the potential V, the energy of $\alpha$-particle will be