1. | wavelength is doubled and frequency becomes half. |
2. | wavelength is halved and frequency remains unchanged. |
3. | wavelength and frequency both remain unchanged. |
4. | wavelength is doubled and frequency unchanged. |
The electric field of an electromagnetic wave in free space is given by –
, where t and x are in seconds and metres respectively. It can be inferred that:
(a) The wavelength λ is 188.4 m
(b) The wave number k is 0.33 rad / m
(c) The wave amplitude is 10 V / m
(d) The wave is propagating along + x direction
Which one of the following pairs of statements is correct?
1. (a) and (b)
2. (b) and (c)
3. (c) and (d)
4. (a) and (c)
The ratio of the amplitude of a magnetic field to the amplitude of an electric field for an electromagnetic wave propagating in a vacuum is equal to:
1. | reciprocal of speed of light in vacuum. |
2. | the ratio of magnetic permeability to the electric susceptibility of vacuum. |
3. | unity. |
4. | the speed of light in a vacuum. |
The electric and magnetic fields of an electromagnetic wave are:
1. | In phase and parallel to each other |
2. | In opposite phases and perpendicular to each other |
3. | In opposite phases and parallel to each other |
4. | In phase and perpendicular to each other |
The velocity of electromagnetic radiation in a medium of permittivity and permeability is given by:
1.
2.
3.
4.
1. | Moving along y-direction with frequency 21 π x 106 Hz and wavelength 200 m. |
2. | Moving along x-direction with frequency 106 Hz and wavelength 100m |
3. | Moving along x-direction with frequency 106 Hz and wavelength 200m |
4. | Moving along x-direction with frequency 106 Hz and wavelength 800m |
Which of the following statement is false for the properties of electromagnetic waves?
1. | Both electric and magnetic field vectors attain the maxima and minima at the same place and same time. |
2. | The energy in the electromagnetic wave is divided equally between electric and magnetic vectors. |
3. | Both electric and magnetic field vectors are parallel to each other and perpendicular to the direction of propagation of the wave. |
4. | These waves do not require any material medium for propagation. |
1. | gamma rays, ultraviolet, infrared, microwaves. |
2. | microwaves, gamma rays, infrared, ultraviolet. |
3. | infrared, microwave, ultraviolet, gamma rays. |
4. | microwave, infrared, ultraviolet, gamma rays. |
The electric and the magnetic fields, associated with an electromagnetic wave, propagating along the positive Z-axis, can be represented by:
1. \(\left [E=E_{0}\hat{k},~B=B_{0}\hat{i} \right ]\)
2. \(\left [E=E_{0}\hat{j},~B=B_{0}\hat{j} \right ]\)
3. \(\left [E=E_{0}\hat{j},~B=B_{0}\hat{k} \right ]\)
4. \(\left [E=E_{0}\hat{i},~B=B_{0}\hat{j} \right ]\)