$A$ radiation is emitted by a $1000 \, W$ bulb and it generates an electric field and magnetic field at point $P$, placed at a distance of $2 \, m$. The efficiency of the bulb is $1.25 \%$. The value of the peak electric field at $P$ is $x \times 10^{-1} \, V/m$. The value of $x$ is (rounded off to the nearest integer).
[Take $\varepsilon_{0} = 8.85 \times 10^{-12} \, C^2 N^{-1} m^{-2}, c = 3 \times 10^8 \, m/s$]

For a plane electromagnetic wave,which of the following quantities has an average value of zero?

Light is an electromagnetic wave. Its speed in vacuum is given by the expression

$A$ cube of unit volume contains $35 \times 10^7$ photons of frequency $10^{15} \text{ Hz}$. If the energy of all the photons is viewed as the average energy being contained in the electromagnetic waves within the same volume,then the amplitude of the magnetic field is $\alpha \times 10^{-9} \text{ T}$. Taking permeability of free space $\mu_0 = 4\pi \times 10^{-7} \text{ Tm/A}$,Planck's constant $h = 6 \times 10^{-34} \text{ Js}$ and $\pi = \frac{22}{7}$,the value of $\alpha$ is $.....$

If $E_{o}$ and $B_{o}$ are the magnitudes of the electric and magnetic fields respectively of an electromagnetic wave in vacuum,then among the following the correct relation is ($\mu_0-$ permeability of free space,$\varepsilon_0-$ permittivity of free space).

The speed of an electromagnetic wave in a medium (whose dielectric constant is $2.25$ and relative permeability is $4$) is equal to .......... $\times 10^8 \, m/s$.