If the energy of a photon with wavelength $6000 \ \mathring{A}$ is $3.32 \times 10^{-19} \ J$, then the energy of a photon with wavelength $4000 \ \mathring{A}$ is ............. $eV$.

If $c$ is the velocity of light in free space,the correct statements about photon among the following are:
$A$. The energy of a photon is $E=h v$.
$B$. The velocity of a photon is $c$.
$C$. The momentum of a photon,$p=\frac{h v}{c}$.
$D$. In a photon-electron collision,both total energy and total momentum are conserved.
$E$. Photon possesses positive charge.
Choose the correct answer from the options given below:

The frequency of a photon with energy $100 \ eV$ is ........... $Hz$. (Given: $h = 6.62 \times 10^{-34} \ J \cdot s$,$1 \ eV = 1.6 \times 10^{-19} \ J$)

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 ........... $\, kg s^{-1}$.

Write the characteristics of a photon or how can a photon of electromagnetic radiation be represented?

What is the velocity of a photon?