Q. No.| 1. | Magnetic field | 2. | Electric field |
| 3. | Both 1 and 2 | 4. | None of these |
In an electromagnetic wave in free space the root mean square value of the electric field is V/m. The peak value of the magnetic field is:
1. 1.41
2.
3.
4.
Out of the following options which one can be used to produce a propagating electromagnetic wave?
1. A stationary charge
2. A chargeless particle
3. An accelerating charge
4. A charge moving at constant velocity
The energy of the EM wave is of the order of \(15\) KeV. To which part of the spectrum does it belong?
1. \(X\text-\)rays
2. Infrared rays
3. Ultraviolet rays
4. \(\gamma\text-\)rays
The electric field associated with an electromagnetic wave in vacuum is given by \(E=40 \cos \left(k z-6 \times 10^8 t\right)\), where \(E\), \(z\), and \(t\) are in volt/m, meter, and second respectively.
The value of the wave vector \(k\) would be:
1. \(2~\text{m}^{-1}\)
2. \(0.5~\text{m}^{-1}\)
3. \(6~\text{m}^{-1}\)
4. \(3~\text{m}^{-1}\)
The ratio of the amplitude of the magnetic field to the amplitude of electric field for an electromagnetic wave propagating in vacuum is equal to
(1) the speed of light in vacuum
(2) reciprocal of speed of light in vacuum
(3) the ratio of magnetic permeability to the electric susceptibility of vacuum
(4) unity
| 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. | \(\left[{E}={E}_0 \hat{i}, ~{B}={{B}_0} \hat{j}\right]\) |
The decreasing order of the wavelength of infrared, microwave, ultraviolet and gamma rays is
(1) gamma rays, ultraviolet, infrared, microwaves
(2) microwaves, gamma rays, infrared, ultraviolet
(3) infrared, microwave, ultraviolet, gamma rays
(4) microwave, infrared, ultraviolet, gamma rays
Which of the following statements 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 the same time
2. The energy in an 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. | The wavelength \(\lambda\) is \(188.4~\text{m}\). |
| 2. | The wave number \(k\) is \(0.33~\text{rad/m}.\) |
| 3. | The wave amplitude is \(10~\text{V/m}\). |
| 4. | The wave is propagating along \(+x\) direction |
Which one of the following pairs of statements is correct?
1. (3) and (4)
2. (1) and (2)
3. (2) and (3)
4. (1) and (3)
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