In an electromagnetic wave, energy density associated with a magnetic field will be:
1.
2.
3.
4.
Which of the following statements is false regarding 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 |
The most penetrating radiation out of the following is:
1. \(X\text-\)rays
2. \(\beta\text-\)rays
3. \(\alpha\text-\)rays
4. \(\gamma\text-\)rays
1. | Faraday's law of induction |
2. | Modified Ampere's law |
3. | Gauss's law of electricity |
4. | Gauss's law of magnetism |
1. | wavelength is \(2\) times and frequency becomes half. |
2. | wavelength is half and frequency remains unchanged. |
3. | wavelength and frequency both remain unchanged. |
4. | None of the above. |
A larger parallel plate capacitor, whose plates have an area of \(1~\text{m}^2,\) separated from each other by \(1\) mm, is being charged at a rate of \(25.8\) V/s.
If the plates have dielectric constant \(10\), then the displacement current at this instant is:
1. \(25~\mu\text{A}\)
2. \(11~\mu\text{A}\)
3. \(2.2~\mu\text{A}\)
4. \(1.1~\mu\text{A}\)
A plane electromagnetic wave travels in free space along \(x\text-\)axis. At a particular point in space, the electric field along \(y\text-\)axis is \(9.3~\text{Vm}^{-1}.\) The magnetic induction is:
1. | \(3.1\times 10^{-8}~\text{T}\) | 2. | \(3\times 10^{-5}~\text{T}\) |
3. | \(3\times 10^{-6}~\text{T}\) | 4. | \(9.3\times 10^{-6}~\text{T}\) |
1. | \(4000~\mathring{A}\). | Ultraviolet light has a wavelength shorter than
2. | Infrared light has a wavelength longer than \(7000~\mathring{A}\). |
3. | Red light has a wavelength near about \(7000~\mathring{A}\). |
4. | Violet light has a wavelength near about \(7000~\mathring{A}\). |
1. | \(36.6\) m | 2. | \(40.5\) m |
3. | \(42.3\) m | 4. | \(50.9\) m |
Assertion (A): | Light can travel in vacuum but sound cannot do so. |
Reason (R): | Light is an electromagnetic wave and sound is a mechanical wave. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | (A) is False but (R) is True. |