Q. No.Two coherent sources of light interfere and produce fringe patterns on a screen. For the central maximum, the phase difference between the two waves will be:
1. zero
2. \(\pi\)
3. \(\dfrac{3\pi}{2}\)
4. \(\dfrac{\pi}{2}\)
1. zero
2. \(\pi\)
3. \(\dfrac{3\pi}{2}\)
4. \(\dfrac{\pi}{2}\)
The Brewster's angle for an interface should be:
1. \(30^{\circ}<i_b<45^{\circ}\)
2. \(45^{\circ}<i_b<90^{\circ}\)
3. \(i_b=90^{\circ}\)
4. \(0^{\circ}<i_b<30^{\circ}\)
1. half
2. four times
3. one-fourth
4. double
1. \(12\)
2. \(6\)
3. \(8\)
4. \(9\)
| 1. | \(60^\circ\) | 2. | \(75^\circ\) |
| 3. | \(30^\circ\) | 4. | \(45^\circ\) |
A monochromatic light of frequency \(500~\text{THz}\) is incident on the slits of Young's double slit experiment. If the distance between the slits is \(0.2~\text{mm}\) and the screen is placed at a distance \(1~\text{m}\) from the slits, the width of \(10\) fringes will be:
| 1. | \(1.5~\text{mm}\) | 2. | \(15~\text{mm}\) |
| 3. | \(30~\text{mm}\) | 4. | \(3~\text{mm}\) |
| 1. | \(\dfrac{I}{2}\) | 2. | \(\dfrac{I}{3}\) |
| 3. | \(\dfrac{3I}{4}\) | 4. | \(\dfrac{2I}{3}\) |
| 1. | angular separation of the fringes increases. |
| 2. | angular separation of the fringes decreases. |
| 3. | linear separation of the fringes increases. |
| 4. | linear separation of the fringes decreases. |
| Statement I: | If screen is moved away from the plane of slits, angular separation of the fringes remains constant. |
| Statement Ii: | If the monochromatic source is replaced by another monochromatic source of larger wavelength, the angular separation of fringes decreases. |
| 1. | Statement I is False but Statement II is True. |
| 2. | Both Statement I and Statement II are True. |
| 3. | Both Statement I and Statement II are False. |
| 4. | Statement I is True but Statement II is False. |
The angular width of the central maximum in the Fraunhofer diffraction for \(\lambda=6000~{\mathring{A}}\) is \(\theta_0.\) When the same slit is illuminated by another monochromatic light, the angular width decreases by \(30\%.\) The wavelength of this light is:
1. \(1800~{\mathring{A}}\)
2. \(4200~{\mathring{A}}\)
3. \(420~{\mathring{A}}\)
4. \(6000~{\mathring{A}}\)
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