$A$ radio transmitter transmits at a frequency of $880 \ kHz$ and consumes $10 \ kW$ of power. The number of photons emitted per second from the transmitter is:

$A$ source $S_1$ is producing $10^{15}$ photons per second of wavelength $5000 \; \mathring{A}$. Another source $S_2$ is producing $1.02 \times 10^{15}$ photons per second of wavelength $5100 \; \mathring{A}$. Then,$(\text{power of } S_2) / (\text{power of } S_1)$ is equal to

Write the equation for the energy of a photon.

There are $n_1$ photons of frequency $\nu_1$ in a beam of light. In an equally energetic beam,there are $n_2$ photons of frequency $\nu_2$. Then the correct relation is

The antiparticle of an electron is:

$A$ scientist claims to have a perfect technique in which he can spontaneously convert an electron completely into energy in the laboratory without any other material required. What is the conclusion about this claim from our current understanding of physics?