$A$ light bulb emits power of $800 \, W$. What is the maximum value of the electric field at a distance of $3.5 \, m$ from the bulb in $V/m$?

If $E$ and $B$ denote electric and magnetic fields respectively,which of the following is dimensionless?

To heat the food containing water,the frequency of the microwaves used in a microwave oven is

$A$ mathematical representation of an electromagnetic wave is given by the two equations $E = E_{max} \cos(kx - \omega t)$ and $B = B_{max} \cos(kx - \omega t)$,where $E_{max}$ is the amplitude of the electric field and $B_{max}$ is the amplitude of the magnetic field. What is the intensity $I$ in terms of $E_{max}$ and universal constants $\mu_0, \epsilon_0$?

An electric charge oscillating harmonically with frequency $750 kHz$ produces electromagnetic waves of frequency. (Speed of light in vacuum is $3 \times 10^8 \ m/s$) (in $kHz$)

When an $EM$ wave propagates through a vacuum,then: