The energy of a photon whose frequency is $10^{12} \text{ MHz}$ is:

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 ............ $MeV$.

The momentum of a photon of energy $1 \text{ MeV}$ in $\text{kg-m/s}$ will be

The rest energy of an electron is

$A$ photon of wavelength $4400 \ \mathring A$ passes through a vacuum. Its effective mass and momentum are,respectively,............

$A$ laser produces a beam of light of frequency $5 \times 10^{14} \,Hz$ with an output power of $33 \,mW$. The average number of photons emitted by the laser per second is (Planck's constant $h = 6.6 \times 10^{-34} \,J \,s$)