Huygens' wave theory allows us to know the:
1. | Wavelength of the wave. |
2. | Velocity of the wave. |
3. | Amplitude of the wave. |
4. | Propagation of wavefront. |
Two coherent sources are \(0.3\) mm apart. They are \(1\) m away from the screen. The second dark fringe is at a distance of \(0.3\) cm from the center. The distance of the fourth bright fringe from the centre is:
1. \(0.6~\text{cm}\)
2. \(0.8~\text{cm}\)
3. \(1.2~\text{cm}\)
4. \(0.12~\text{cm}\)
Light waves of intensities \(I\) and \(9I\) interfere to produce a fringe pattern on a screen. The phase difference between the waves at point \(P\) is \(\frac{3\pi}{2}\) and \(2\pi\) at other point \(Q\). The ratio of intensities at \(P\) and \(Q\) is:
1. \(8:5\)
2. \(5:8\)
3. \(1:4\)
4. \(9:1\)
Two light sources are said to be coherent when their:
1. | amplitudes are equal and have a constant phase difference. |
2. | wavelengths are equal. |
3. | intensities are equal. |
4. | frequencies are equal and have a constant phase difference. |
Five identical polaroids are placed coaxially with \(45^{\circ}\) angular separation between pass axes of adjacent polaroids as shown in the figure. (\(I_0\): Intensity of unpolarized light)
The intensity of light, \(I\),
emerging out of the \(5\)th polaroid is:
1. | \(\dfrac{I_0}{4}\) | 2. | \(\dfrac{I_0}{8}\) |
3. | \(\dfrac{I_0}{16}\) | 4. | \(\dfrac{I_0}{32}\) |
1. | \(\dfrac{1}{\sqrt{3}}\) | 2. | \(\dfrac{3}{2}\) |
3. | \(\sqrt{3}\) | 4. | \(\dfrac{\sqrt{3}}{2}\) |
Unpolarized light of intensity \(32\) Wm–2 passes through three polarizers such that the transmission axes of the first and second polarizer make an angle of \(30^{\circ}\) with each other and the transmission axis of the last polarizer is crossed with that of the first. The intensity of the final emerging light will be:
1. \(32\) Wm–2
2. \(3\) Wm–2
3. \(8\) Wm–2
4. \(4\) Wm–2
1. | \(\theta\) increases. |
2. | \(\theta\) remains unchanged. |
3. | \(\theta\) decreases. |
4. | \(\theta\) increases or decreases depending on the intensity of light. |
1. | \(\dfrac{I_0}{4}\) | 2. | \(\dfrac{I_0}{8}\) |
3. | \(\dfrac{I_0}{16}\) | 4. | \(\dfrac{I_0}{2}\) |