$A$ photon of frequency $f$ has a momentum associated with it. If $c$ is the velocity of light,the momentum is:

$(a)$ When monochromatic light is incident on a surface separating two media,the reflected and refracted light both have the same frequency as the incident frequency. Explain why?
$(b)$ When light travels from a rarer to a denser medium,the speed decreases. Does the reduction in speed imply a reduction in the energy carried by the light wave?
$(c)$ In the wave picture of light,intensity of light is determined by the square of the amplitude of the wave. What determines the intensity of light in the photon picture of light?

The rest energy of an electron is $0.511 \, MeV$. The electron is accelerated from rest to a velocity $0.5 \, c$. The change in its energy will be ............ $MeV$.

What is the relationship between the number of photons and the intensity of radiation?

An $AIR$ station is broadcasting waves of wavelength $300 \ m$. If the radiating power of the transmitter is $10 \ kW$,then the number of photons radiated per second is:

$A$ photon,an electron,and a uranium nucleus all have the same wavelength. The one with the most energy is: