Q. No.One side of an equilateral prism is painted by transparent material of refractive index \(n_2\). The refractive index of prism is \(1.6\). The minimum value of \(n_2\) required for total internal reflection from painted face is:
1. \(3 \sqrt{3} / 1.6 \)
2. \(\sqrt{3}\)
3. \(3.2 / \sqrt{3} \)
4. \(4 \sqrt{3} / 5\)
1. \(3 \sqrt{3} / 1.6 \)
2. \(\sqrt{3}\)
3. \(3.2 / \sqrt{3} \)
4. \(4 \sqrt{3} / 5\)
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Angle of minimum deviation is equal to the half of the angle of prism in an equilateral prism. The refractive index of the prism is:
1. \(1.5\)
2. \(\sqrt{3}\)
3. \(\sqrt{2}\)
4. \(1.65\)
1. \(1.5\)
2. \(\sqrt{3}\)
3. \(\sqrt{2}\)
4. \(1.65\)
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For a thin symmetric prism made of glass (refractive index \(1.5\)), the ratio of incident angle and minimum deviation will be:
1. \(3:4\)
2. \(3:2\)
3. \(2:1\)
4. \(1:2\)
1. \(3:4\)
2. \(3:2\)
3. \(2:1\)
4. \(1:2\)
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A ray of light passing through an equilateral prism is having velocity \(2.12 \times 10^8 ~\text{m/s} \) in the prism material, then the minimum angle of deviation is: (in degrees)
1. \(45\)
2. \(30\)
3. \(28\)
4. \(58\)
1. \(45\)
2. \(30\)
3. \(28\)
4. \(58\)
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As shown in the diagram, when the incident ray is parallel to base of the prism, the emergent ray grazes along the second surface.
If refractive index of the material of prism is \(\sqrt{2},\) the angle \(\theta\) of prism is:
1. \(60^{\circ}\)
2. \(75^{\circ}\)
3. \(90^{\circ}\)
4. \(45^{\circ}\)
If refractive index of the material of prism is \(\sqrt{2},\) the angle \(\theta\) of prism is:
1. \(60^{\circ}\)
2. \(75^{\circ}\)
3. \(90^{\circ}\)
4. \(45^{\circ}\)
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Consider an equilateral prism (refractive index\(\sqrt{2}\) ). A ray of light is incident on its one surface at a certain angle \(i\). If the emergent ray is found to graze along the other surface, then the angle of refraction at the incident surface is close to:
1. \(15^\circ\)
2. \(20^\circ\)
3. \(40^\circ\)
4. \(30^\circ\)
1. \(15^\circ\)
2. \(20^\circ\)
3. \(40^\circ\)
4. \(30^\circ\)
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A thin prism with angle \(5^{\circ}\) of refractive index \(1.72\) is combined with another prism of refractive index \(1.9\) to produce dispersion without deviation. The angle of second prism is:
1. \(4.5^{\circ}\)
2. \(6^{\circ}\)
3. \(4^{\circ}\)
4. \(5^{\circ}\)
1. \(4.5^{\circ}\)
2. \(6^{\circ}\)
3. \(4^{\circ}\)
4. \(5^{\circ}\)
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A prism of angle \(75^{\circ}\) and refractive index \(\sqrt{3}\) is coated with thin film of refractive index \(1.5\) only at the back exit surface. To have total internal reflection at the back exit surface the incident angle must be:
\(\left[\sin15^{\circ}= 0.25, \sin25^{\circ}= 0.43\right]\)
1. between \(15^{\circ}\) and \(20^{\circ}\)
2. \(15^{\circ}\)
3. \(>25^{\circ}\)
4. Both \((1)\) and \((2)\)
\(\left[\sin15^{\circ}= 0.25, \sin25^{\circ}= 0.43\right]\)
1. between \(15^{\circ}\) and \(20^{\circ}\)
2. \(15^{\circ}\)
3. \(>25^{\circ}\)
4. Both \((1)\) and \((2)\)
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The exit surface of a prism with refractive index \(n\) is coated with a material having refractive index \(\dfrac{n}{2}.\) When this prism is set for minimum angle of deviation it exactly meets the condition of critical angle. The prism angle is:
1. \(60^\circ\)
2. \(15^\circ\)
3. \(30^\circ\)
4. \(45^\circ\)
1. \(60^\circ\)
2. \(15^\circ\)
3. \(30^\circ\)
4. \(45^\circ\)
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For a transparent prism, if the angle of minimum deviation is equal to its refracting angle, the refractive index \(n\) of the prism satisfies.
1. \(\sqrt 2 < n < 2 \sqrt 2\)
2. \(1 < n < 2\)
3. \(n \geq 2 \)
4. \(\sqrt{2}<n <2\)
1. \(\sqrt 2 < n < 2 \sqrt 2\)
2. \(1 < n < 2\)
3. \(n \geq 2 \)
4. \(\sqrt{2}<n <2\)
Subtopic: Prisms |
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