Q. No.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. \(30^{\circ}<i_b<45^{\circ}\)
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 |
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. | \(\dfrac{\pi}{2}\) |
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. | \(6000~{\mathring{A}}\) |
In Young's double-slit experiment, if there is no initial phase difference between the light from the two slits, a point on the screen corresponding to the fifth minimum has a path difference:
| 1. | \( \dfrac{5\lambda}{2} \) | 2. | \( \dfrac{10\lambda}{2} \) |
| 3. | \( \dfrac{9\lambda}{2} \) | 4. | \( \dfrac{11\lambda}{2} \) |
1. \(1.15~\mathring{A}\)
2. \(0.75~\mathring{A}\)
3. \(0.55~\mathring{A}\)
4. \(2.1~\mathring{A}\)
1. \(2.8 \times 10^{-8}~\text{m}\)
2. \(5.6 \times 10^{-8}~\text{m}\)
3. \(1.4 \times 10^{-8}~\text{m}\)
4. \(7.6 \times 10^{-8}~\text{m} \)
In a double-slit experiment, when the light of wavelength \(400~\text{nm}\) was used, the angular width of the first minima formed on a screen placed \(1~\text{m}\) away, was found to be \(0.2^{\circ}.\) What will be the angular width of the first minima, if the entire experimental apparatus is immersed in water? \(\left(\mu_{\text{water}} = \dfrac{4}{3}\right)\)
1. \(0.1^{\circ}\)
2. \(0.266^{\circ}\)
3. \(0.15^{\circ}\)
4. \(0.05^{\circ}\)
Two periodic waves of intensities I1 and I2 pass through a region at the same time in the same direction. The sum of the maximum and minimum intensities is:
1.
2.
3.
4.
| 1. | The angular width of the central maximum of the diffraction pattern will increase. |
| 2. | The angular width of the central maximum will decrease. |
| 3. | The angular width of the central maximum will be unaffected. |
| 4. | A diffraction pattern is not observed on the screen in the case of electrons. |
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