Absolute and Relative Refractive Index

Q.

Light enters from air into diamond which has a refractive index of 2.42. Calculate the speed of light in diamond. The speed of light in air is 3.0 x ${10}^{8}m{s}^{-1}$.

Q.

The speed of light in water is 2.25 x ${10}^{8}m/s$. If the speed of light in vacuum be 3 x ${10}^{8}m/s$, calculate the refractive index of water.

Q.

The refractive index of water with respect to air is $\frac{4}{3}$ . What is the refractive index of air with respect to water?

Q.

Define refractive index, absolute refractive index, and relative refractive index.

Q.

Absolute Refractive Index of a Medium - Definition

Q.

The refractive index of glass for light going from air to glass is $\frac{3}{2}.$ Glass to air will be :

(a) $\frac{2}{3}$

(b) $\frac{4}{5}$

(c) $\frac{4}{6}$

(d) $\frac{5}{2}$

Q.

What is the unit of the refractive index?

Q.

The speed of light in air is 3 $\times {10}^{8}m{s}^{-1}$. Calculate the speed of light in glass. The refractive index of glass is 1.5.

Q.

The speed of light in diamond is 125, 000 km $m{s}^{-1}$. What is its refractive index? (Speed of light in air = 3 $\times {10}^{8}m{s}^{-1}$ )

Q.

Give three examples of materials that refract light rays. What happens to the speed of light rays when they enter these materials ?

Q.

How is the refractive index of a medium related to the speed of light in it and in vacuum or air?

Q.

Refractive index depends on the __________of light

Q.

Define the refractive index of a medium. What is its SI unit?

Q.

The refractive index of glass is 1.5. What does it mean?

Q.

(a) State the laws of refraction of light. Give an expression to relate the absolute refractive index of a medium with speed of light in vacuum.

(b) The refractive indices of water and glass with respect to air are $\raisebox{1ex}{$4$}\!\left/ \!\raisebox{-1ex}{$3$}\right.$ and $\raisebox{1ex}{$3$}\!\left/ \!\raisebox{-1ex}{$2$}\right.$ respectively. If the speed of light in glass is $2\times {10}^{8}m{s}^{-1}$, find the speed of light in (i) air, (ii) water.

Q.

A ray of light gets dispersed into visible spectrum [VIBGYOR], when it is passed through a prism. Which color wavelength deviates the most?

1. Voilet

2. Red

3. Green

4. Yelllow

Q.

The refractive indices of four substances P, Q, R and S are 1.50, 1.36, 1.77 and 1.31 respectively. The speed of light is the maximum in the substance : (a) P (b) Q (c) R (d) S

Q.

Which has higher refractive index : water or glass ?

Q.

It is known that light from a distant star takes 10 years to reach the Earth. How far is this star situated from the Earth?

a) 9.467 $\times$ ${10}^{16}$ km

b) 9.467 $\times$ ${10}^{16}$​ m

c) 10 light years

1. both (b) and (c)

2. only a

3. only b

4. both (a) and (c)

Q.

A postage stamp appears raised by 7.0 mm when placed under a rectangular glass block of refractive index 1.5. The thickness of the glass block is

1. 21 mm

2. 1.5 mm

3. 70 mm

4. 3.0 mm

Q.

What are the units which are used to measure distance in space? Explain them briefly.

Q. 1 astronomical unit is greater than 1 light year.

1. True
2. False

Q.

Proxima Centauri is the nearest known star to the Sun. It is situated at a distance of 4.24 light years from the Sun. How many kilometers is it away from the Sun?

Q.

The refractive index of water with respect to air is a${}^{\mu }w$ and a glass with respect to air is a${}^{\mu }g$. Express the refractive index of glass with respect to water.

Q.

The following table gives the refractive indices of a few media : $\begin{array}{cccccc}& 1& 2& 3& 4& 5\\ Medium:& Water& Crownglass& Rocksalt& Ruby& Diamond\\ Refreactiveindex:& 1.33& 1.52& 1.54& 1.71& 2.42\end{array}$

Use this table to give an example of : (i) a medium pair so that light speeds up when it goes from one of these medium to another. (it) a medium pair so that light slows down when it goes from one of these medium to another.

Q.

The speed of light in turpentine oil is $2.04\times {10}^{5}km/s$. Calculate the refractive index of turpentine oil.

Q.

Derive the value of 1 light year.

Q.

A ray of light strikes the surface of a rectangular glass block such that the angle of incidence is 0°, the path taken by the ray in each case as it passes through the glass block and emerges from it is such that

1. Light does not suffer lateral displacement but only angular deviation

2. Light neither suffers lateral displacement nor angular deviation

3. Light suffers lateral displacement as well as angular deviation

4. Light suffers no angular deviation but only lateral displacement

Q.

The ratio of velocity of light in first medium to that of velocity of light in second medium is …………

Q.

Define the term.

Refractive index