If the energy of the photon is increased by a factor of $4$,then its momentum

What is the unit of energy in atomic and nuclear physics? Define it.

There are two sources of light,each emitting with a power of $100 \, W$. One emits $X$-rays of wavelength $1 \, nm$ and the other visible light at $500 \, nm$. Find the ratio of the number of photons of $X$-rays to the photons of visible light of the given wavelength.

Which of the following will have the least value of $\frac{q}{m}$?

Assertion: Mass of a moving photon varies inversely as the wavelength.
Reason: Energy of the particle $= \text{mass} \times (\text{speed of light})^2$

Monochromatic light of frequency $6.0 \times 10^{14} \;Hz$ is produced by a laser. The power emitted is $2.0 \times 10^{-3} \;W$.
$(a)$ What is the energy of a photon in the light beam?
$(b)$ How many photons per second,on an average,are emitted by the source?