The frequency of a photon, having energy $100eV$ is$(h = 6.6\,{10^{ - 34}}\,J{\rm{ - }}sec)$
$2.42 \times {10^{26}}Hz$
$2.42 \times {10^{16}}Hz$
$2.42 \times {10^{12}}Hz$
$2.42 \times {10^9}Hz$
A photon falls through a height of $1 \,km$ through the earth's gravitational field. To calculate the change in its frequency, take its mass to be $h v / c^{2}$. The fractional change in frequency $v$ is close to
Explain particle-wave (dual) nature of matter.
The work function of aluminium is $4.2eV.$ If two photons, each of energy $3.5 eV$strike an electron of aluminium, then emission of electrons will be
Rest mass energy of an electron is $0.51\ MeV.$ If this electron is moving with a velocity $0.8\ c$ (where $c$ is velocity of light in vacuum), then kinetic energy of the electron should be. ........... $MeV$
A $200\, W$ sodium street lamp emits yellow light of wavelength $0.6\, \mu \,m$. Assuming it to be $50\%$ efficient in converting electrical energy to light, the number of photon of yellow light it emits per second is