In a plane $EM$ wave, the electric field oscillates sinusoidally at a frequency of $5 \times 10^{10} \mathrm{~Hz}$ and an amplitude of $50 \mathrm{Vm}^{-1}$. The total average energy density of the electromagnetic field of the wave is :
[Use $\varepsilon_0=8.85 \times 10^{-12} \mathrm{C}^2 / \mathrm{Nm}^2$ ]
$1.106 \times 10^{-8} \mathrm{Jm}^{-3}$
$4.425 \times 10^{-8} \mathrm{Jm}^{-3}$
$2.212 \times 10^{-8} \mathrm{Jm}^{-3}$
$2.212 \times 10^{-10} \mathrm{Jm}^{-3}$
An electromagnetic wave with frequency $\omega $ and wavelength $\lambda $ travels in the $+ y$ direction . Its magnetic field is along $+\, x-$ axis. The vector equation for the associated electric field ( of amplitude $E_0$) is
If the magnetic field of a light wave oscillates parallel to $y-$ axis and is given by $B_y = B_m\,sin\,(kz -\omega t)$, the direction of wave travel and the axis along which the electric vector oscillates is
A red $LED$ emits light at $0.1$ watt uniformly around it. The amplitude of the electric field of the light at a distance of $1\ m$ from the diode is....$ Vm^{-1}$
Assume a bulb of efficiency $2.5\%$ as a point source. The peak values of electric field produced by the radiation coming from a $100\, W$ bulb at a distance of $3\, m$ is respectively.....$V\,{m^{ - 1}}$
Which of the following statement is false for the properties of electromagnetic waves ?