Two superposing waves are represented by the following equations:
\({\mathrm{y}_1=5 \sin 2 \pi(10 \mathrm{t}-0.1 \mathrm{x}), \mathrm{y}_2=10 \sin 2 \pi(10 \mathrm{t}-0.1 \mathrm{x}).}\)
Ratio of intensities will be:
1. 1
2. 9
3. 4
4. 16
In Young's double-slit experiment the light emitted from the source has = 6.5 × 10–7 m and the distance between the two slits is 1 mm. The distance between the screen and slits is 1 metre. Distance between third dark and fifth bright fringe will be:
1. 3.2 mm
2. 1.63 mm
3. 0.585 mm
4. 2.31 mm
In Young's double-slit experiment, the slit separation is doubled. This results in:
1. | An increase in fringe intensity |
2. | A decrease in fringe intensity |
3. | Halving of the fringe spacing |
4. | Doubling of the fringe spacing |
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° 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
On superposition of two waves \(y_{1}=3sin\left ( \omega t-kx \right )\) and \(y_{2}=4sin\left ( \omega t-kx+\frac{\pi }{2} \right )\) at a point, the amplitude of the resulting wave will be:
1. 7
2. 5
3.
4. 6.5
If the polarising angle for a material is , then the refractive index of the material will be:
1.
2.
3.
4.
Five identical polaroids are placed coaxially with \(45^{\circ}\) angular separation between pass axes of adjacent polaroids as shown in the figure. (I0: Intensity of unpolarized light)
The intensity of light, I,
emerging out of the 5th polaroid is:
1.
2.
3.
4.
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. |
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 and 2 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 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 cm
2. 0.8 cm
3. 1.2 cm
4. 0.12 cm