Laws of Refraction

Q.

A ray of light passes from vacuum into a medium of refractive index $\mu$. If the angle of incidence is found to be twice the angle of refraction, then the angle of incidence is:($\text{sin}2r=2\text{sin}r\text{cos}r$)

1. ${\text{cos}}^{-1}\left(\frac{\mu }{2}\right)$

2. $2{\text{cos}}^{-1}\left(\frac{\mu }{2}\right)$

3. $2{\text{sin}}^{-1}\left(\mu \right)$

4. $2{\text{sin}}^{-1}\left(\frac{\mu }{2}\right)$

Q.

The speed of light in water and glass is 2.2×10⁸ m/s and 2×10^⁸ m/s, respectively. What is the refractive index of glass with respect to water?

1. 1

2. 1.1

3. 0.909

4. 0.8

Q. The refractive index of ice is 1.31 and that of rock salt is 1.54. Calculate the refractive index of rock salt with respect to the refractive index of ice.

Q.

What causes the refraction of light?

Q.

Define critical angle.

Q. What is refracted ray?

Q.

The absolute refractive index of a medium with respect to air is given by :

[c = speed of light in air, v = speed of light in the medium]

1. None of above

2. $n_m$ = $\frac{v}{c}$

3. $n_m$ = $\frac{c}{v}$

4. $n_m$ = $\frac{c^2}{v}$

Q.

Light enters from air to dense flint glass with a refractive index of $1.65$. What will be the speed of light in flint glass?

Q. Question 29
Draw a ray diagram showing the path of rays of light when it enters with oblique incidence (i) from air into water; (ii) from water into air.

Q. State the laws of refraction.

Q.

Refractive index of diamond is 2.42 and that of glass is 1.5. Calculate the critical angle for diamond-glass surface.

Q.

How to find the refractive index of one medium in respect to the other medium

Q.

What is meant by the 'angle of incidence' and the 'angle of refraction' for a ray of light ? Draw a labelled ray diagram to show the angle of incidence and the angle of refraction for a refracted ray of light.

Q.

Is there any difference between the refractive index of ice & water ?

Q.

A ray of light enters a glass slab PQRS, as shown in the diagram. The critical angle of the glass is 42°. What will happen to light when it strikes surface PQ?

1. It will undergo Total internal refraction

2. It will undergo regular refraction

3. It will undergo critical phenomenon

4. It will undergo Total internal reflection

Q.

A straight line along which light travels is called a light ____________ .

Q.

A ray of light travelling in air is incident on the plane of a transparent medium. The angle of incidence is ${45}^{\circ }$ and that of refraction is ${30}^{\circ }$. Find the refractive index of the medium.

1. 2

2. 1

3. $\sqrt{2}$

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

Q.

A light ray does not bend at the boundary in passing from one medium to the other medium if the angle of incidence is:

(a) $0^{\circ }\left(b\right){45}^{\circ }\left(c\right){60}^{\circ }\left(d\right){90}^{\circ }$

Q. Define refraction and state the laws of refraction.

Q.

How is the reflection of light ray from a plane mirror different from the refraction of light ray as it enters a block of glass ?

Q.

When a ray of light travelling in glass enters into water obliquely : (a) it is refracted towards the normal (b) it is not refracted at all (c) it goes along the normal (d) it is refracted away from the normal

Q. A light ray from air strikes an unknown medium at angle 60° as shown. If the angle of refraction is 30°. Evaluate the refractive index of the medium.

1. $\sqrt{2}$
2. $\sqrt{3}$
3. $\sqrt{5}$
4. $\sqrt{7}$

Q. A light ray travels through three medias as shown. Which of the following shows the ascending order of their refractive indices?

1. $n_2,n_3,n_1$
2. $n_1,n_2,n_3$
3. $n_1,n_3,n_2$
4. $n_3,n_1,n_2$

Q.

Refractive index between two media is related to:

1. Speed of light in both the mediums

2. Angle of incidence and angle of refraction

3. Both (a) and (b)

4. Neither (a) nor (b)

Q.

Given that i is angle of incidence and r is angle of refraction for a light ray at a boundary, the correct expression for Snell's Law is:

1. $\sin i={\sin }^{2}r$

2. $\sin i=k\sin r$
   [where k = constant]

3. $\cos i=k\cos r$
   [k = constant]

4. $\sin r={\sin }^{2}i$

Q. How does the refractive index of a transparent medium affect the speed of light passing through it?

Q. Choose the optically denser medium from the given figure:​​​​​​.

1. Medium 2
2. Medium 1
3. Both media have the same optical density
4. Cannot be determined

Q.

Light travels more quickly through water than through glass. (a) Which is optically denser : water or glass ? (b) If a ray of light passes from glass into water, which way will it bend : towards the normal or away from the normal ?

Q. What is meant by refraction of light? State the laws of refraction.

Q. A ray of light travelling in air is incident on the plane of a transparent medium. The angle of incidence is ${45}^{\circ }$ and that of refraction is ${30}^{\circ }$. Find the refractive index of the medium.

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