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:
Doubled
Quadrupled
Zero
Halved
The time taken by a photoelectron to come Out after the photon strikes is approximately
Find the number of electrons emitted per second by a $24 \,W$ source of monochromatic light of wavelength $6600 \mathring A$, assuming $3 \%$ efficiency for photoelectric effect (take $h=6.6 \times 10^{-34} \,Js$ ) $S$
The rest mass of the photon is
The momentum of a photon in an $X-$ ray beam of ${10^{ - 10}}$ metre wavelength is
In photoelectric effect, the electrons are ejected from metals if the incident light has a certain minimum