The refractive index of the material of a prism is and the angle of the prism is \(30^\circ.\) One of the two refracting surfaces of the prism is made a mirror inwards with a silver coating. A beam of monochromatic light entering the prism from the other face will retrace its path (after reflection from the silvered surface) if the angle of incidence on the prism is:
1. | \(60^\circ\) | 2. | \(45^\circ\) |
3. | \(30^\circ\) | 4. | zero |
A thin prism having refracting angle \(10^\circ\) is made of glass of a refractive index \(1.42\). This prism is combined with another thin prism of glass with a refractive index \(1.7\). This combination produces dispersion without deviation. The refracting angle of the second prism should be:
1. \(6^{\circ}\)
2. \(8^{\circ}\)
3. \(10^{\circ}\)
4. \(4^{\circ}\)
The angle of incidence for a ray of light at a refracting surface of a prism is 45°. The angle of prism is 60°. If the ray suffers minimum deviation through the prism, the angle of deviation and refracting index of the material of the prism respectively are
(a)30°,
(b)45°,
(c)30°,
(d)45°,
1. | \(45^{0},~\sqrt{2}\) | 2. | \(30^{0},~\sqrt{2}\) |
3. | \(30^{0},~\frac{1}{\sqrt{2}}\) | 4. | \(45^{0},~\frac{1}{\sqrt{2}}\) |