The energy of E.M. wave is due to their 

1.  Wavelength

2.  Frequency

3.  The electric and magnetic field

4.  None of these 

Which of the following rays are not electromagnetic waves?
1. $\mathrm{\gamma }$-rays

2. $\mathrm{\beta }$-rays

3. Heat rays

4. X-rays

The sun light strikes the upper atmosphere of earth with intensity 1.38 Kw/$m^2$. The peak value of electric field at that point will be- (in kilovolt/meter)

1. 2.04                                 2. 4.08

3. 8.16                                 4. 1.02

The magnitude of electric field at 10 meter distance apart from a source is 100 volt/meter in electromagnetic waves being emitted by a point source. The electric field at point 20 meter from the source will be :

1. 100 volt/m                                                   2. 200 volt/m

3. 50 volt/m                                                    4. 25 volt/m

The displacement current flows in the dielectric of a capacitor when the potential difference between its plates:-

1.  is changing with time.

2.  is changing with distance.

3.  becomes zero.

4.  has assumed a constant value.

Assertion: For cooking in a microwave oven, food is always kept in metal containers

Reason: The energy of microwave is easily transferred to the food in metal container

What is the magnitude of momentum that is contained in a unit volume for an electromagnetic wave:

1.  $\overrightarrow{\mathrm{E}}\times \overrightarrow{\mathrm{B}}$

2.  ${\mathrm{\epsilon }}_0 \left(\overrightarrow{\mathrm{E}}\times \overrightarrow{\mathrm{B}}\right)$

3.  ${\mathrm{\mu }}_0 \left(\overrightarrow{\mathrm{E}}\times \overrightarrow{\mathrm{B}}\right)$

4.  $\sqrt{{\mathrm{\mu }}_0{\mathrm{\epsilon }}_0} \left(\overrightarrow{\mathrm{E}}\times \overrightarrow{\mathrm{B}}\right)$

Out of the following options which one can be used to produce a propagating electromagnetic wave?