Light with an energy flux of \(25\times10^4\) Wm^–2 falls on a perfectly reflecting surface at normal incidence. If the surface area is \(15\) cm², the average force exerted on the surface is:
1. \(1.25\times 10^{-6}\) N
2. \(2.50\times 10^{-6}\) N$$
3. \(1.20\times 10^{-6}\) N$\mathrm{}$
4. \(3.0\times 10^{-6}\) N

The ratio of the amplitude of a magnetic field to the amplitude of an electric field for an electromagnetic wave propagating in a vacuum is equal to:

The electric and the magnetic fields, associated with an electromagnetic wave, propagating along the positive Z-axis, can be represented by:
1. \(\left [E=E_{0}\hat{k},~B=B_{0}\hat{i} \right ]\)
2. \(\left [E=E_{0}\hat{j},~B=B_{0}\hat{j} \right ]\)
3. \(\left [E=E_{0}\hat{j},~B=B_{0}\hat{k} \right ]\)
4. \(\left [E=E_{0}\hat{i},~B=B_{0}\hat{j} \right ]\)

Which of the following statement is false for the properties of electromagnetic waves?

The electric field of an electromagnetic wave in free space is given by –
$\overrightarrow{E}=10$ $\cos$ $({10}^{7}t+kx)$ $\hat{j}$ $V/m$, where t and x are in seconds and metres respectively. It can be inferred that:

(a) The wavelength λ is 188.4 m
(b) The wave number k is 0.33 rad / m
(c) The wave amplitude is 10 V / m
(d) The wave is propagating along + x direction

Which one of the following pairs of statements is correct?

1. (a) and (b)

2. (b) and (c)

3. (c) and (d)

4. (a) and (c)

The velocity of electromagnetic radiation in a medium of permittivity ${\epsilon }_0$ and permeability ${\mu }_0$ is given by:

1.  $\sqrt{\frac{{\mathrm{\epsilon }}_{\mathrm{o}}}{{\mathrm{\mu }}_{\mathrm{o}}}}$

2.  $\sqrt{{\mathrm{\mu }}_{\mathrm{o}}{\mathrm{\epsilon }}_{\mathrm{o}}}$

3.  $\frac{1}{\sqrt{{\mathrm{\mu }}_{\mathrm{o}}{\mathrm{\epsilon }}_{\mathrm{o}}}}$

4.  $\sqrt{\frac{{\mathrm{\mu }}_{\mathrm{o}}}{{\mathrm{\epsilon }}_{\mathrm{o}}}}$