Which one statement is incorrect about the electromagnetic waves?
(1) gives always the direction of propagation
(2) is always perpendicular to
(3) Transverse in nature
(4) is always parallel to
Instantaneous displacement current of \(2.0\) A is set up in the space between two parallel plates of \(1~\mu \text{F}\) capacitor. The rate of change in potential difference across the capacitor is:
1. \(3\times 10^{6}~\text{V/s}\)
2. \(4\times 10^{6}~\text{V/s}\)
3. \(2\times 10^{6}~\text{V/s}\)
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. | \(\frac{B_0}{E_0}=c\) |
Displacement current is:
1. | continuous, when the electric field is changing in the circuit. |
2. | continuous, when the magnetic field is changing in the circuit. |
3. | continuous in both types of fields. |
4. | continuous through wires and resistance only. |
A radiowave has a maximum magnetic field induction of T on arrival at a receiving antenna. The maximum electric field intensity of such a wave is
(1) zero
(2)
(3)
(4)
1. | \(2\) A | 2. | \(3\) A |
3. | \(6\) A | 4. | \(9\) A |
The shortest wavelength is for
(1) -rays
(2) X-rays
(3) ultraviolet rays
(4) microwaves
An accelerated charge :
(1) emits an electromagnetic wave
(2) does not emit electromagnetic wave
(3) produces a gravitational field
(4) None of these
The electromagnetic radiations are in descending order of wavelength in the following sequences :
(1) infra-red waves, radio waves, X-rays, visible light rays
(2) Radio-waves, infra-red waves, visible light rays, X-rays
(3) Radio waves, visible light rays, infra-red waves, X-rays
(4) X-rays, visible light rays, infra-red wave, radio-waves
X-rays and -rays are both electromagnetic waves, which one of the following statements is true?
(1) in general, X-rays have a larger wavelength than that of -rays
(2) X-rays have a smaller wavelength than that of -rays
(3) -rays have smaller frequency than that of X-rays
(4) wavelength and frequency of X-rays are both larger than those of -rays.