The ratio of contributions made by the electric field and magnetic field components to the intensity of an EM wave is:

1. c : 1

2. ${\mathrm{c}}^2$ : 1

3. 1 : 1

4. $\sqrt{\mathrm{c}}$ : 1

An EM wave radiates outwards from a dipole antenna, with \(E_0\), as the amplitude of its electric field vector. The electric field \(E_0\), which transports significant energy from the source falls off as:
1. \(\dfrac{1}{r^3}\)
2. \(\dfrac{1}{r^2}\)
3. \(\dfrac{1}{r}\)
4. remains constant

Choose the correct options:
1. (b), (c)
2. (a), (c)
3. (a), (d)
4. (c), (d)

A plane electromagnetic wave propagating along x-direction can have the following pairs of E and B.

(a) E_x, B_y
(b) E_y, B_z
(c) B_x, E_y
(d) E_z, B_y

1. (b, c)
2. (a, c)
3. (b, d)
4. (c, d)

If E and B represent electric and magnetic field vectors of the electromagnetic wave, the direction of propagation of the electromagnetic wave is along:

1. E

2. B

3. B x E

4. E x B

The electric field produced by the radiations coming from \(100~\text{W}\) bulb at a \(3~\text{m}\) distance is \(E\). The electric field intensity produced by the radiations coming from \(50~\text{W}\) bulb at the same distance is:
1. \(\dfrac{E}{2}\)
2. \(2E\)
3. \(\dfrac{E}{\sqrt2}\)
4. \(\sqrt2E\)

Light with an energy flux of \(20~\text{W/cm}^2\)${\mathrm{}}^{}$ falls on a non-reflecting surface at normal incidence. If the surface has an area of \(30~\text{cm}^2\)${\mathrm{}}^{}$, the momentum delivered (for complete absorption) during \(30\) minutes is:
1. \(36\times10^{-5}~\text{kg-m/s}\)
2. \(36\times10^{-4}~\text{kg-m/s}\)
3. \(108\times10^{4}~\text{kg-m/s}\)
4. \(1.08\times10^{7}~\text{kg-m/s}\)

A linearly polarised electromagnetic wave given as $\mathrm{E}={\mathrm{E}}_0 \hat{\mathrm{i}} \cos (\mathrm{kz}-\mathrm{\omega t})$ is incident normally on a perfectly reflecting infinite wall at z = a. Assuming that the material of the wall is optically inactive, the reflected wave will be given as:

1. ${\mathbf{E}}_{\mathbf{r}}=-{\mathrm{E}}_0\hat{\mathrm{i}}\cos \hspace{0.17em}(\mathrm{kz}-\mathrm{\omega t})$

2. ${\mathbf{E}}_{\mathbf{r}}={\mathrm{E}}_0\hat{\mathrm{i}}\cos (\mathrm{kz}+\mathrm{\omega t})$

3. ${\mathbf{E}}_{\mathbf{r}}=-{\mathrm{E}}_0\hat{\mathrm{i}}\cos (\mathrm{kz}+\mathrm{\omega t})$

4. ${\mathbf{E}}_{\mathbf{r}}={\mathrm{E}}_0\hat{\mathrm{i}}\sin (\mathrm{kz}-\mathrm{\omega t})$

One requires \(11\) eV of energy to dissociate a carbon monoxide molecule into carbon and oxygen atoms. The minimum frequency of the appropriate electromagnetic radiation to achieve the dissociation lies in:
1. visible region
2. infrared region
3. ultraviolet region
4. microwave region