$A$ transmitter of $100 \ W$ power emits electromagnetic waves of wavelength $540 \ nm$. How many photons are emitted per second? (Given: $h = 6 \times 10^{-34} \ J \cdot s$,$c = 3 \times 10^8 \ m/s$)

Which of the following statements is $NOT$ true?

The momentum of a photon with frequency $1.5 \times 10^{13} \ Hz$ is .......

If $h$ is Planck's constant in $SI$ system,the momentum of a photon of wavelength $0.01 \, \mathring{A}$ is:

Solar energy is incident normally on the earth's surface at the rate of about $1.4 \, kW m^{-2}$. The distance between the earth and the sun is $1.5 \times 10^{11} \, m$. Energy $E$ and mass $m$ are related by Einstein's equation $E = mc^2$,where $c = 3 \times 10^8 \, m s^{-1}$ is the speed of light in free space. The decrease in the mass of the sun is ........... $\, kg s^{-1}$.

The energy of a photon of visible light with the maximum wavelength in $eV$ is approximately .......