A $160 \,W$ infrared source is radiating light of wavelength $50000 \,\mathring A$ uniformly in all directions. The photon flux at a distance of $1.8 \,m$ is the order of ............. $m^{-2} s ^{-1}$
$10$
$10^{10}$
$10^{15}$
$10^{20}$
Photon and electron are given same energy $({10^{ - 20}}J)$. Wavelength associated with photon and electron are ${\lambda _{Ph}}$ and ${\lambda _{el}}$ then correct statement will be
There are ${n_1}$ photons of frequency ${\gamma _1}$ in a beam of light. In an equally energetic beam, there are ${n_2}$ photons of frequency ${\gamma _2}$. Then the correct relation is
If a photon has velocity $c$ and frequency $\nu$, then which of following represents its wavelength
A hydrogen atom initially in the ground level absorbs a photon, which excites it to the $n = 4$ level. Determine the wavelength and frequency of photon.
In a photoelectric effect experiment a light of frequency $1.5$ times the threshold frequency is made to fall on the surface of photosensitive material. Now if the frequency is halved and intensity is doubled, the number of photo electrons emitted will be: