Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev

Class 10 Physics Solutions By Lakhmir Singh & Manjit Kaur

Class 10 : Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev

The document Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev is a part of the Class 10 Course Class 10 Physics Solutions By Lakhmir Singh & Manjit Kaur.
All you need of Class 10 at this link: Class 10

Lakhmir Singh Physics Class 10 Solutions Page No:227

Question 1: What name is given to the ratio of sine of angle of incidence to the sine of angle of refraction ?

Solution : Refractive index.

Question 2: Write the relation between the angle of incidence and the angle of refraction for a medium.

Solution : Refractive index = sine of the angle of incidence/sine of the angle of refraction.


Lakhmir Singh Physics Class 10 Solutions Page No:228

Question 3: What is the unit of refractive index ?

Solution : Refractive index has no units.

Question 4: Which has higher refractive index : water or glass ?

Solution : Glass has higher refractive index.

Question 5: Refractive indices of carbon disulphide and ethyl alcohol are 1.63 and 1.36 respectively. Which is optically denser ?

Solution : Carbon disulphide is more denser than the ethyl alcohol.

Question 6: The refractive index of diamond is 2.42. What is the meaning of this statement in relation to the speed of light ?

Solution : This means that the ratio of the speed of light in air to the speed of light in diamond is equal to 2.42.

Question 7: If the refractive index for light going from air to diamond be 2.42, what will be the refractive index for light going from diamond to air ?

Solution :

Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev

Question 8: How is the refractive index of a material related to the speed of light in it ?

Solution : Refractive index of a material  Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev

Question 9: Fill in the following blank with a suitable word :
 When a ray of light goes from air into a clear material, you see the ray bend. How much the ray bends is determined by the………………………. of the material.

Solution : Refractive index.

Question 10: Give three examples of materials that refract light rays. What happens to the speed of light rays when they enter these materials ?

Solution : Three examples of materials that refract light rays are water, glass and diamond. When light rays (travelling in air) enter these materials, their speed decreases.

Question 11: Define Snell’s law of refraction. A ray of light is incident on a glass slab at an angle of incidence of 60°. If the angle of refraction be 32.7°, calculate the refractive index of glass. (Given : sin 60° = 0.866, and sin 32.7° = 540).

Solution : Snell's law: According to the Snell's law of refraction, the ratio of sine of angle of incidence to the sine of angle of refraction is constant for a given pair of media. 

Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev

Given: Angle of incidence = 60°
Angle of refraction = 32.4° 

Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev

Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev

Question 12: The speed of light in vacuum and in two different glasses is given in the table below :

Medium
Speed of light
Vaccume
Flint glass
crown glass
3.00 x 10m/s
1.86 x 108 m/s
1.97 x 108 m/s


(a) Calculate the absolute refractive indexes of flint glass and crown glass.
 (b) Calculate the relative refractive index for light going from crown glass to flint glass.

Solution :

Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev
Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev

Question 13: The speed of light in air is 3 × 108 m/s. In medium X its speed is 2 × 108 m/s and in medium Y the speed of light is 2.5 × 108 m/s. Calculate:
 (a) air nx (b) air ny (c) xny

Solution :

Given: Speed of light in air = 3.0x108m/s
Speed of light in medium X = 2.0x108m/s
Speed of light in medium Y = 2.50x108m/s

(a) airnx = ? 

Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev
Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev
Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev

Question 14: What is the speed of light in a medium of refractive index 6/5 if its speed in air is 3,00,000 km/s ?

Solution : Refractive index of medium = 6/5 = 1.2
Speed of light in air = 3,00.000km/s

We know that 

Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev
Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev

Question 15: The refractive index of glass is 1.5. Calculate the speed of light in glass. The speed of light in air is 3.0 × 108ms-1.

Solution : Given:-Refractive index of glass = 1.5
Speed of light in air = 3.0x108m/s

We know that 

Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev

Question 16: The speed of light in water is 2.25 × 108 m/s. If the speed of light in vacuum be 3 × 108 m/s, calculate the refractive index of water.

Solution :  Speed of light in vacuum = 3.0x108m/s
Speed of light in water = 2.25 x108m/s 
Refractive index of water = ?

We know that 

Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev

Question 17: 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 × 108 ms-1.

Solution : Given:- Refractive index of diamond = 2.42
Speed of light in air = 3.0x108m/s We know that

Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev

Question 18: (a) State and explain the laws of refraction of light with the help of a labelled diagram.
 (b) What is meant by the refractive index of a substance ?
 (c) Light travels through air at 300 million ms-1. On entering water it slows down to 225 million ms-1

Calculate the refractive index of water.

Solution : 

(a) Law of refraction

Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev

First law: According to the first law of refraction, the incident ray. the refracted ray and the normal at the point of incidence, all lie in the same plane. 

Second law: According to the second law of refraction, the ratio of the sine of angle of Incidence to the sine of angle of refraction is constant for a given pair of media. 

(b) Refractive index of substance: The ratio of speed of light In vacuum to the speed of light In a medium. Is called the refractive index of that medium. 

(c) Speed of light in air = 300 milion m/sec

Speed of light in water = 225 milion m/sec

We know that 

Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh, Class 10 Class 10 Notes | EduRev

Offer running on EduRev: Apply code STAYHOME200 to get INR 200 off on our premium plan EduRev Infinity!

Complete Syllabus of Class 10

Dynamic Test

Content Category

Related Searches

Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh

,

mock tests for examination

,

MCQs

,

Summary

,

Free

,

Sample Paper

,

past year papers

,

Previous Year Questions with Solutions

,

practice quizzes

,

Class 10 Class 10 Notes | EduRev

,

Exam

,

study material

,

Important questions

,

video lectures

,

Semester Notes

,

pdf

,

Class 10 Class 10 Notes | EduRev

,

Viva Questions

,

ppt

,

Extra Questions

,

Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh

,

Objective type Questions

,

shortcuts and tricks

,

Solutions of Refraction of Light (Page No- 227 & 228) - Physics By Lakhmir Singh

,

Class 10 Class 10 Notes | EduRev

;