Deviation in Prism

Q. A ray of light is incident at angle $i$ on a surface of a prism of small angle $A$ and emerges normally from the opposite surface. If the refractive index of the material of the prism is $\mu$, the angle of incidence $i$ is nearly equal to:

1. $\frac{A}{\mu }$
2. $\frac{A}{\left(2\mu \right)}$
3. $\mu A$
4. $\mu \frac{A}{2}$

Q. If one face of a prism of angle ${30}^{\circ }$ and refractive index $\mu =\sqrt{2}$ is silvered, the incident ray retraces its initial path. The angle of incidence is

1. ${45}^{\circ }$
2. ${30}^{\circ }$
3. ${60}^{\circ }$
4. ${15}^{\circ }$

Q.

The refractive index of the material of a prism is $\sqrt{2}$ and the angle of the prism is 30°. One of the two refracting surfaces of the prism is made a mirror facing inwards by 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 its angle of incidence on the prism is

1. 60°
2. 45°
3. 30°
4. 0°

Q. a ray of light is incident at 60 degree on a face of prism of angle 30 degree and the emergent ray makes 30 degree with the incident ray. the refractive index of prism is [a] 1.732 [b] 1.414 [c] 1.5 [d] 1.33

Q. A thin prism having refracting angle ${10}^o$ is made of glass of refractive index $1.42$. This prism is combined with another thin prism of glass of refractive index $1.7$. This combination produces dispersion without deviation. The refracting angle of second prism should be

1. ${10}^o$
2. $4^o$
3. $6^o$
4. $8^o$

Q. A ray of light is incident grazingly at one face of an equilateral prism. If the emerges grazingly at the other face. The refractive index of the prism is

Q. A ray of light incident on an equilateral prism ( refractive index=√3) moves parallel to base of prism inside it. What is the angle of incidence for this ray ?

Q. The ratio of resolving power of an optical microscope for two wavelengths ${\lambda }_1=4000\AA$ and ${\lambda }_2=6000\AA$ is

1. 9:4
2. 3:2
3. 16:81
4. 8:27

Q. The light ray is incident at an angle of ${60}^{\circ }$ on a prism of angle ${45}^{\circ }$. When the light ray falls on the other surface at ${90}^{\circ }$, the refractive index of the material of prism $\mu$ and the angle of deviation $\delta$ are given by

1. $\mu =\sqrt{2},\delta ={30}^{\circ }$
2. $\mu =1.5,\delta ={15}^{\circ }$
3. $\mu =\frac{\sqrt{2}}{2},\delta ={30}^{\circ }$
4. $\mu =\sqrt{\frac{3}{2}},\delta ={15}^{\circ }$

Q.

A prism is made of glass of unknown refractive index. A parallel beam of light is incident on a face of the prism. The angle of minimum deviation is measured to be 40°. What is the refractive index of the material of the prism? The refracting angle of the prism is 60°. If the prism is placed in water (refractive index 1.33), predict the new angle of minimum deviation of a parallel beam of light.

Q.

Monochromatic light is incident on a glass prism of angle A. If the refractive index of the material of the prism is μ, a ray, incident at an angle q, on the face AB would get transmitted through the face AC of the prism provided:

1. 

2. 

3. 

4. 

Q. A monochromatic light is incident from air on a refracting surface of a prism of angle ${75}^o$ and refractive index $n_0=\sqrt{3}$. The other refracting surface of the prism is coated by a thin film of material of refractive index n as shown in figure. The light suffers total internal reflection at the coated prism surface for an incidence angle of $\theta \le {60}^o$. The value of $n^2$ is .

Q. An isosceles prism of angle ${120}^{\circ }$ has a refractive index $\sqrt{2}$. Two parallel monochromatic rays enter the prism parallel to each other in air as shown. in figure. Find the angle between the emerging rays

1. ${30}^{\circ }$
2. ${45}^{\circ }$
3. ${60}^{\circ }$
4. ${90}^{\circ }$

Q.

For an isosceles prism of angle $A$ and refractive index $\mu$, it is found that the angle of minimum deviation ${\delta }_m=A$. Which of the following option(s) is/are correct?

1. At minimum deviation, the incident angle $i_1$ and the refracting angle $r_1$ at the first refracting surface are related by $r_1=\left(i_1/2\right)$

2. For this prism the refractive index $\mu$ and the angle of prism A are related as $A=\frac{1}{2}{\cos }^{-1}\left(\frac{\mu }{2}\right)$

3. For this prism, the emergent ray at the second surface will be tangential to the surface when the angle of incidence at the first surface is $i_1={\sin }^{-1}[\sin A\sqrt{4{\cos }^2\frac{A}{2}-1}-\cos A]$

4. For the angle of incidence $i_1=A$, the ray inside the prism is parallel to the base of the prism

Q. (a) A ray 'PQ' of light is incident on the face AB of a glass prism ABC (as shown in the figure) and emerges out of the face AC. Trace the path of the ray. Show that $\angle i+\angle e=\angle A+\angle \delta$. When $\delta$ and e denote the angle of deviation and angle of emergence respectively.



Plot a graph showing the variation of the angle of deviation as a function of angle of incidence. State the condition under which $\delta$ is minimum.

(b) Find out the relation between the refractive index ($\mu$) of the glass prism and $\angle A$ for the case when the angle of prism (A) is equal to the angle of minimum deviation $\left({\delta }_m\right)$. Hence obtain the value of the refractive index for angle of prism $A={60}^{\circ }$.

Q. One of the refracting surfaces of a prism of angle ${30}^{\circ }$ is silvered. A ray of light incident at an angle of ${60}^{\circ }$ retraces its path. The refractive index of the material of prism is

1. $2$
2. $\sqrt{2}$
3. $\sqrt{3}$
4. $\frac{3}{2}$

Q. Angle of prism is ${30}^{\circ }$ and its refractive index is $\sqrt{2}$ and one of the refracting faces is silvered. At what angle of incidence, a ray should be incident on one surface so that after reflection from the silvered surface, it retraces its path

1. ${60}^{\circ }$
2. ${45}^{\circ }$
3. ${30}^{\circ }$
4. $si{n}^{-1}\sqrt{1.5}$

Q. A ray of light passes through an equilateral prism $(\mu =1.5)$ such that the angle of incidence is equal to the angle of emergence & the either is equal to $\frac{3}{4}th$ of the angle of prism. Calculate angle of deviation.

1. ${30}^{\circ }$
2. ${45}^{\circ }$
3. ${20}^{\circ }$
4. ${60}^{\circ }$

Q. 10.A ray of light incident at an angle of 60^° on one face of Prism whose angle of Prism is 30^° . The ray emerging out of the Prism makes an angle 30^° with incident Ray. Show that emergent ray is perpendicular to the face through which it emerges and calculate the refractive index of the material of Prism.

Q. The critical angle for materialof a prism is 45^° and its refracting angle is 30^°.A monochromatic ray goes out perpendicular to the surface of emergence.Then angle of incidence onthe prism will be

Q. A thin prism $P_1$ with angle $6^{\circ }$ and made from glass of refractive index $1.54$ is combined with another thin prism $P_2$ of refractive index $1.72$ to produce dispersion without deviation. The angle of prism $P_2$ will be

1. $5^{\circ }{24}^{\prime }$
2. $4^{\circ }{30}^{\prime }$
3. $6^{\circ }$
4. $8^{\circ }$

Q. A prism ABC of angle ${30}^{\circ }$ has its face AC silvered. A ray of light incident at an angle of ${45}^{\circ }$ at the face AB retraces its path after refraction at face AB and reflection at face AC. The refractive index of the material of the prism is

1. 1.5
2. 3/√2
3. √2
4. 4/3

Q.

Which is the position of minimum deviation in prism?

Q. A ray of light passes through an equilateral glass prism in such a manner that the angle of incidence is equal to the angle of emergence and each of these angles is equal to $\frac{3}{4}$ of the angle of the prism. The angle of deviation is

1. ${45}^{\circ }$
2. ${30}^{\circ }$
3. ${20}^{\circ }$
4. ${39}^{\circ }$

Q. A prism having refractive index $\sqrt{2}$ and refracting angle ${30}^{\circ }$, has one of the refracting surface polished. A beam of light incident on the other refracting surface will retrace its path, if the angle of incidence is :

1. $0^{\circ }$
2. ${30}^{\circ }$
3. ${45}^{\circ }$
4. ${60}^{\circ }$

Q. An equilateral triangle prism is made of glass refractive index=1.5 . A ray of light is incident normally on one of the faces . The angle between the incident and emergent ray is

Q. A ray of light undergoes deviation of ${30}^{\circ }$ when incident on an equilateral prism of refractive index $\sqrt{2}$. The angle made by the ray inside the prism with the base of the prism is

1. ${15}^{\circ }$
2. $0^{\circ }$
3. ${45}^{\circ }$
4. ${30}^{\circ }$

Q. If angle of minimum deviation by an equilateral prism is equal to its prism angle, then the refractive index of material of prism can be

1. $1.12$
2. $1.73$
3. $1.40$
4. $1.08$

Q.

A deviation of$2°$ is produced in the yellow ray when the prism of crown and flint glass are chromatically combined. Taking dispersive powers of crown and flint glass as $0.02$ and $0.03$ respectively and refractive index for yellow light for these glasses are $1.5$ and $1.6$respectively. The refracting angles for crown glass prism will be _______$°$ (in $degree$). (Round off to the Nearest Integer)

Q.

Two transparent slabs having equal thickness but different refractive indices ${\mu }_1$ and \$m{u}_2$ are pasted side by side to form a composite slab. this slab is placed just after the double slit in a young's experiment so that the light from the other slit goes through the other material. What should be the minimum thickness of the slab so that there is a minimum at the point $P_0$ which is equidistant from th eslits ?