Assertion (A): | Radio waves can be polarised. |
Reason (R): | Sound waves in the air are longitudinal in nature. |
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. | Both (A) and (R) are False. |
The expression for intensity (as shown in the figure) of transmitted light when a polaroid sheet is rotated between two crossed polaroids is:
[Given: \(I_0\) is the intensity of transmitted light from polariser \(\mathrm{A}\)]
1. | \(I = \dfrac{I_{0}}{2} \sin^{2} 2 \theta\) | 2. | \(I = \dfrac{I_{0}}{4} \sin^{2} 2 \theta\) |
3. | \(I = \dfrac{I_{0}}{2} \cos^{2} 2 \theta\) | 4. | \(I = \dfrac{I_{0}}{4} \cos^{2} 2 \theta\) |
1. | \(\dfrac{{I}_0}{16}\) | 2. | \(\dfrac{{I}_0}4\) |
3. | \(\dfrac{{I}_0}2\) | 4. | \(\dfrac{{I}_0}{32}\) |
1. | the refracted light will be completely polarised. |
2. | both the reflected and refracted light will be completely polarised. |
3. | the reflected light will be completely polarised but the refracted light will be partially polarised. |
4. | the reflected light will be partially polarised. |