When an $X$-ray photon collides with a proton,its frequency:

The wavelength of a photon is $5000 \mathring A$. Its energy will be:

The fact that photons carry energy was established by

Number of photons of equal energy emitted per second by a $6 \ mW$ laser source operating at $663 \ nm$ is . . . . . . . (Given: $h=6.63\times10^{-34} \ J.s$ and $c=3\times10^{8} \ m/s$)

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:

$A$ $10\, kW$ transmitter emits radio waves of wavelength $500\, m$. The number of photons emitted per second by the transmitter is of the order of