Dimension of $\frac{1}{\mu_0 \varepsilon_0}$ should be equal to

In fog, photographs of the objects taken with infrared radiations are more clear than those obtained during visible light because

If the intensity of an electromagnetic wave is $0.02 \ W/m^2$ and its velocity in free space is $3 \times 10^8 \ m/s$,then the energy density of the radiation is ..... $J/m^3$.

If $E$ and $H$ represent the intensity of the electric field and the magnetising field respectively,then the unit of $E/H$ will be:

$A$ plane electromagnetic wave is incident on a surface. If this wave transfers momentum $P$ and energy $U$ to the surface,then:

An electromagnetic wave of frequency $3 \, GHz$ enters a dielectric medium of relative electric permittivity $2.25$ from vacuum. The wavelength of this wave in that medium will be $....... \times 10^{-2} \, cm$.