The amplitude of the electric field associated with a light beam of intensity $\frac{15}{\pi} \text{ W m}^{-2}$ is (in $\text{ N C}^{-1}$)

The peak electric field produced by the radiation coming from the $80\, W$ bulb at a distance of $10\, m$ is $\frac{x}{10} \sqrt{\frac{\mu_{0} c }{\pi}} \,\frac{ V }{ m }$. The efficiency of the bulb is $10\, \%$ and it is a point source. The value of $x$ is ...... .

The nature of electromagnetic waves is .......

An electromagnetic wave of wavelength $2 \times 10^{-10} \,m$ passes from vacuum into a dielectric medium of relative permittivity $4$. Then its wavelength will be

An electromagnetic wave has its electric and magnetic fields given by $\vec{E}(t) = \vec{E}_m \sin(kx - \omega t)$ and $\vec{B}(t) = \vec{B}_m \sin(kx - \omega t)$. If the directions of $\vec{E}_m$ and $\vec{B}_m$ are in the direction of $\hat{i} + \hat{j}$ and $\hat{i} - \hat{j}$ respectively,the unit vector that gives the direction of propagation of the wave is:

Consider the following:
$I.$ Waves created on the surfaces of a water pond by a vibrating source.
$II.$ Wave created by an oscillating electric field in air.
$III.$ Sound waves travelling under water.
Which of these can be polarized?