According to einstein’s theory, how does an increase in the number of photons affect a beam of light? the wavelength of the beam of light increases. the speed of the beam of light increases. the brightness of the beam of light increases. the frequency of the light beam increases. the energy of each photon in the beam of light increases.

The brightness of the beam of light increases.

Explanation:

As per Einstein's experimental verification he proves that light is of particle nature and his equation for energy balance is given as

so incident photons on a photosensitive plate will eject the electrons from the plate with some sufficient KE.

So here light is considered as particles which means one photon will eject one electron. So here intensity of light is considered as

Intensity = (number of photons per second) (energy of one photon)

so it is given as

now if the intensity of light is increased for same wavelength of light then it means the number of photon must have to be increase.

so correct answer will be

The brightness of the beam of light increases.

correct it is c.) b b