When an airplane flies over a television antenna,the picture on the $TV$ screen appears to flicker or shake slightly. This is due to:

The electromagnetic flux from the Sun reaching the Earth is $10^3 \ W m^{-2}$. What is the power incident on a roof of dimensions $6 \ m \times 30 \ m$?

$A$ $100 \ W$ electric bulb produces electromagnetic radiation with an electric field amplitude of $2 \ V \ m^{-1}$ at a distance of $10 \ m$. Assuming it as a point source, estimate the efficiency of the bulb. (in $\%$)

Assertion : Microwaves are better carrier of signals than optical waves.
Reason : Microwaves move faster than optical waves.

$A$ long straight wire of resistance $R$,radius $a$,and length $l$ carries a constant current $I$. The Poynting vector for the wire will be

$A$ physical quantity $\vec{S}$ is defined as $\vec{S}=(\vec{E} \times \vec{B}) / \mu_0$,where $\vec{E}$ is the electric field,$\vec{B}$ is the magnetic field,and $\mu_0$ is the permeability of free space. The dimensions of $\vec{S}$ are the same as the dimensions of which of the following quantity(ies)?
$(A)$ $\frac{\text{Energy}}{\text{charge} \times \text{current}}$
$(B)$ $\frac{\text{Force}}{\text{Length} \times \text{Time}}$
$(C)$ $\frac{\text{Energy}}{\text{Volume}}$
$(D)$ $\frac{\text{Power}}{\text{Area}}$