If an electromagnetic wave propagating through vacuum is described by \(E_y= E_0 sin(kx-\omega t); ~B_z= B_0sin(kx-\omega t),\)then:
1. \(E_0k=B_0\omega\)
2. \(E_0B_0 = \omega k\)
3. \(E_0\omega= B_0k\)
4. \(E_0B_0= \frac{\omega}{k}\)

A charged particle oscillates about its mean equilibrium position with a frequency of ${10}^9 \mathrm{Hz}$. The electromagnetic waves produced:

(a) will have frequency of ${10}^9 \mathrm{Hz}$
(b) will have frequency of $2\times {10}^9 \mathrm{Hz}$
(c) will have wavelength of 0.3 m
(d) fall in the region of radiowaves

Choose the correct option

1. (a, b, c)

2. (a, c, d)

3. (b, c, d)

4. (c, d)

The source of electromagnetic waves can be a charge:

(a) moving with a constant velocity
(b) moving in a circular orbit
(c) at rest
(d) falling in an electric field

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

An EM wave of intensity \(I\) falls on a surface kept in a vacuum and exerts radiation pressure \(P\) on it. Which of the following are true?

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

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

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

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. \(1.08\times10^{7}~\text{kg-m/s}\)

The electric field intensity produced by the radiations coming from 100 W bulb at a 3 m distance is E. The electric field intensity produced by the radiations coming from 50 W bulb at the same distance is:

1. \(\frac{E}{2}\)

2. \(2E\)

3. \(\frac{E}{\sqrt2}\)

4. \(\sqrt2E\)

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 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