Long distance short-wave radio broadcasting uses

An electric bulb is rated as $200 \, W$. What will be the peak magnetic field $(\times 10^{-8} \, T)$ at $4 \, m$ distance produced by the radiations coming from this bulb? Consider this bulb as a point source with $3.5 \%$ efficiency.

In an electromagnetic wave,the amplitude of the electric field is $1 \ V/m$ and the frequency of the wave is $5 \times 10^{14} \ Hz$. The wave propagates in the positive $Z$-direction. The average energy density of the electric field in this wave is ........ $J \ m^{-3}$.

The magnetic field in a plane electromagnetic wave is given by, $B_{y} = 2 \times 10^{-7} \sin (\pi \times 10^{3} x + 3 \pi \times 10^{11} t) \; T$. Calculate the wavelength.

$A$ plane electromagnetic wave is incident on a material surface. If the wave delivers momentum $p$ and energy $E$,then

Assertion $(A)$: Electromagnetic waves exert pressure,called radiation pressure.
Reason $(R)$: This is because they carry energy.