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 $6 \ m \times 30 \ m$?

According to the theoretical study of radiation from a linear antenna,the power radiated is proportional to $[\lambda = \text{wavelength}]$

$5 \%$ of the power of a $100 \, W$ bulb is converted to visible radiation. The average intensity of visible radiation at a distance of $10 \, m$ from the bulb is .......... $W/m^2$.

$A$ 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)?
$(A)$ $\frac{\text{Energy}}{\text{charge} \times \text{current}}$
$(B)$ $\frac{\text{Force}}{\text{Length} \times \text{Time}}$
$(C)$ $\frac{\text{Energy}}{\text{Volume}}$
$(D)$ $\frac{\text{Power}}{\text{Area}}$

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

The dimensional formula for the physical quantity $\frac{E^2 \mu_0 \varepsilon_0}{B^2}$ is ($E =$ electric field and $B =$ magnetic field).