The velocity factor of a transmission line is $x$. If the dielectric constant of the medium is $2.6$,the value of $x$ is:

$A$ point source of $100\,W$ emits light with $5\%$ efficiency. At a distance of $5\,m$ from the source,the intensity produced by the electric field component is:

The average value of electric energy density in an electromagnetic wave is. [where $E_0$ is peak value]

If ${\varepsilon _0}$ and ${\mu _0}$ are respectively the electric permittivity and the magnetic permeability of free space,and ${\varepsilon}$ and ${\mu}$ are the corresponding quantities in a medium,the refractive index of the medium is:

Which of the following is not a property of light?

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 $....... \times 10^{-2} \, cm$.