If a source of electromagnetic radiation having power $15 kW$ produces $10^{16}$ photons per second, the radiation belongs to a part of spectrum is.(Take Planck constant $h =6 \times 10^{-34}\,Js$ )

In a plane electromagnetic wave travelling in free space, the electric field component oscillates sinusoidally at a frequency of $2.0 \times 10^{10}\,Hz$ and amplitude $48\,Vm ^{-1}$. Then the amplitude of oscillating magnetic field is : (Speed of light in free space $=3 \times 10^8\,m s ^{-1}$)

For plan electromagnetic waves propagating in the $z-$ direction, which one of the following combination gives the correct possible direction for $\vec E$ and $\vec B$ field respectively?

In an electromagnetic wave the energy density associated with magnetic field will be

An antenna is placed in a dielectric medium of dielectric constant $6.25$. If the maximum size of that antenna is $5.0\, mm$. it can radiate a signal of minimum frequency of $GHz .$

(Given $\mu_{ r }=1$ for dielectric medium)

A plane electromagnetic wave of frequency $100\, MHz$ is travelling in vacuum along the $x -$ direction. At a particular point in space and time, $\overrightarrow{ B }=2.0 \times 10^{-8} \hat{ k } T$. (where, $\hat{ k }$ is unit vector along $z-$direction) What is $\overrightarrow{ E }$ at this point ?