Q. No.
If an electromagnetic wave going through a medium is given by;
\(E=E_{0}sin\left ( kx-\omega t \right )\) and \(B=B_{0}sin\left ( kx-\omega t \right ),\) then:
| 1. | |
| 2. | If the electric field is in the z-direction then the magnetic field should be in the -y direction |
| 3. | Both 1 and 2 are correct |
| 4. | Only 1 is correct |
Consider an electric charge oscillating with a frequency of 10 MHz. The radiation emitted will have a wavelength equal to:
| 1. | 20 m | 2. | 30 m |
| 3. | 40 m | 4. | 10 m |
Which of the following electromagnetic waves has minimum frequency?
1. Radio waves
2. Infrared waves
3. Microwaves
4. X-rays
A parallel plate capacitor consists of two circular plates each of radius 12 cm and separated by 5.0 mm. The capacitor is being charged by an external source. The charging current is constant and is equal to 0.15 A. The rate of change of the potential difference between the plates will be:
| 1. | \(1.873 \times 10^7 \mathrm{~V} / \mathrm{s}\) |
| 2. | \(1.873 \times 10^8 \mathrm{~V} / \mathrm{s}\) |
| 3. | \(1.873 \times 10^9 \mathrm{~V} / \mathrm{s}\) |
| 4. | \(1.873 \times 10^{10} \mathrm{~V} / \mathrm{s}\) |
A lamp emits monochromatic green light uniformly in all directions. The lamp is 3% efficient in converting electrical power to electromagnetic waves and consumes 100 W of power. The amplitude of the electric field associated with the electromagnetic radiation at a distance of 5 m from the lamp will be:
1. 1.34 V/m
2. 2.68 V/m
3. 4.02 V/m
4. 5.36 V/m
A variable frequency AC source is connected to a capacitor. Then on increasing the frequency:
| 1. | Both conduction current and displacement current will increase |
| 2. | Both conduction current and displacement current will decrease |
| 3. | Conduction current will increase and displacement current will decrease |
| 4. | Conduction current will decrease and displacement current will increase |
Instantaneous displacement current of 2.0 A is set up in the space between two parallel plates of \(1~\mu F\) capacitor. The rate of change in potential difference across the capacitor is:
1.
2.
3.
4. None of these
Which statement is incorrect?
| 1. | Speed of light in free space \(=\frac{1}{\sqrt{\mu_0 \epsilon_0}}\) |
| 2. | Speed of light in the medium \(=\frac{1}{\sqrt{\mu \epsilon}}\) |
| 3. | \(\frac{E_0}{B_0}=c\) |
| 4. | \(\frac{B_0}{E_0}=c\) |
A capacitor is having a capacity of 2 pF. The electric potential across the capacitor is changing with a value of \(10^{12}~\mathrm{V/s}\). The displacement current is:
| 1. | 2 A | 2. | 3 A |
| 3. | 6 A | 4. | 9 A |
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