Refractive Index

Q. Question 2
Light enters from air to glass having refractive index 1.50. What is the speed of light in the glass? The speed of light in vacuum is $3\times {10}^{8}m{s}^{-1}$.

Q. Question 4
You are given kerosene, turpentine and water. In which of these does the light travel fastest? Use the information given in the table.

$\begin{array}{cccc}Materialmedium& Refractiveindex& Materialmedium& Refractiveindex\\ Air& 1.0003& CanadaBalsam& 1.53\\ Ice& 1.31& -& -\\ Water& 1.33& Rocksalt& 1.54\\ Alcohol& 1.36& -& -\\ Kerosene& 1.44& Carbondisulphide& 1.63\\ Fusedquartz& 1.46& Denseflintglass& 1.65\\ Turpentineoil& 1.47& Ruby& 1.71\\ Benzene& 1.50& Sapphire& 1.77\\ Crownglass& 1.52& Diamond& 2.42\end{array}$

Q. All formulas of chapter light reflection and refraction

Q.

Question 3
Find out, from the table, the medium having highest optical density. Also, find the medium with lowest optical density.

$\begin{array}{cccc}Materialmedium& Refractiveindex& Materialmedium& Refractiveindex\\ Air& 1.0003& CanadaBalsam& 1.53\\ Ice& 1.31& -& -\\ Water& 1.33& Rocksalt& 1.54\\ Alcohol& 1.36& -& -\\ Kerosene& 1.44& Carbondisulphide& 1.63\\ Fusedquartz& 1.46& Denseflintglass& 1.65\\ Turpentineoil& 1.47& Ruby& 1.71\\ Benzene& 1.50& Sapphire& 1.77\\ Crownglass& 1.52& Diamond& 2.42\end{array}$

Q.

Light enters from air to glass having a refractive index of $1.50$. What is the speed of light in the glass? The speed of light in vacuum is $3\times {10}^8\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$s$}\right.$.

Q.

How is the refractive index of a medium related to the speed of light? Obtain an expression for the refractive index of a medium with respect to another in terms of speed of light in these two media?

Q.

The refractive index of diamond is 2.42 what is the meaning of this statement in relation to the speed of light.

Q.

What is the difference between Fresnel and Fraunhofer diffraction?

Q.

Name two factors on which the refractive index of a medium depends? State how does it depend on the factors stated by you.

Q.

Define the term refractive index of a medium. Can it be less than 1?

Q.

Draw a ray diagram to show the refraction of light through a glass prism.

On the diagram mark a) Incident angle b) emergent ray c) angle of deviation. [3 MARKS]

Q. Refractive index(RI) of glass is 1.5 and that of water is 1.33.
What is the RI of glass with respect to water?
What is the RI of water with respect to glass?

Q. A transparent solid cylindrical rod has a refractive index of $\frac{2}{\sqrt{3}}.$ It is surrounded by air. A light ray is incident at the mid point of one end of the rod as shown in the figure.

The incident angle $\theta$ for which the light ray grazes along the wall of the rod is

1. $si{n}^{-1}\left(\frac{1}{2}\right)$
2. $si{n}^{-1}\left(\frac{\sqrt{3}}{2}\right)$
3. $si{n}^{-1}\left(\frac{1}{\sqrt{3}}\right)$
4. $si{n}^{-1}\left(\frac{2}{\sqrt{3}}\right)$

Q. A biconvex lens has radii of curvature 20 cm each. If the refractive index of the material of the lens is 1.5, what is its focal length?

1. -10 cm
2. 20 cm
3. 10 cm
4. -20 cm

Q.

The refractive index of water with respect to air is 1.33. The refractive index of air with respect to water will be

1. $0.25$

2. $0.50$

3. $1.00$

4. $0.75$

Q.

A ray of light traveling in the air enters obliquely into water. Does the light ray bend towards the normal or away from the normal? Why?

Q. If the absolute refractive index of water is $\frac{4}{3}$ and that of glass is $\frac{3}{2}$. Find the refractive index of glass with respect to water.

1. $\frac{9}{8}$
2. $\frac{4}{5}$
3. $\frac{8}{9}$
4. $\frac{5}{4}$

Q.

The refractive index of water is $\frac{4}{3}$. The speed of light in water is:

(Take the speed of light in air $=3\times {10}^{8}m{s}^{-1}$)

1. $2.25\times {10}^{8}m{s}^{-1}$
2. $2\times {10}^{8}m{s}^{-1}$
3. $3\times {10}^{8}m{s}^{-1}$
4. $2.5\times {10}^{8}m{s}^{-1}$

Q.

What is the speed of light in a medium of refractive index $\frac{6}{5}$ if its speed in air is 3, 00, 000 km/s ?

Q. As the refractive index of a medium increases, the speed of light in that medium .

1. increases
2. decreases
3. remains constant

Q.

The dispersive power of a prism depends upon:

1. Shape of prism

2. Material of prism

3. Height of prism

4. Angle of prism

Q.

The highest refractive index is of :

(a) Glass (b) Water

(c) Diamond (d) Ruby.

Q.

When light travels from rarer to denser medium, speed decreases, and when it comes out from denser medium speed increases...we know that if a body changes its speed or acceleration.. force needs to be applied...so which force makes it to speed up or slow down..while going through denser to rarer...which force acts on it to increase the speed???

Q.

The refractive indices of four media A, B, C and D are 1.44, 1.52, 1.65 and 1.36 respectively. When light travelling in air is incident in these media at equal angles, the angle of refraction will be the minimum : (a) in medium A (b) in medium B (c) in medium C (d) in medium D

Q.

The refractive index of water is : (a) 1.33 (b) 1.50 (c) 2.42 (d) 1.36

Q.

How does the refractive index of a medium depend on the wavelength of light used?

Q.

The refractive index of a converging lens is$1.4$. What will be the focal length of this lens if it is placed in a medium of the same refractive index? Assume the radii of curvature of the faces of the lens are $R_1$and $R_2$ respectively.

1. Zero

2. $\frac{R_1{R}_2}{R_1-R_2}$

3. Infinite

4. $1$

Q.

Explain the term fresnel distance.

Q.

The velocity of light in glass ($\mu =1.5$) is $2\times {10}^{8}m/s$ and in certain liquid($\mu =1.2$), the velocity of light found to be $2.50\times {10}^{8}m/s$. Then the refractive index of the liquid with respect to glass is $0.8$

1. True

2. False

Q.

A ray of light is incident on a glass plate at an angle of ${60}^{\circ }$. If the reflected and the refracted rays are mutually perpendicular, then the refractive index of material is

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

2. $\sqrt{3}$

3. $\frac{3}{2}$

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