Class 10 Physics Chapter 3
Refraction of light
Important Questions

Refraction of light is a phenomenon in the realm of optics. It occurs when light, which travels at different speeds in various mediums, changes its direction as it crosses the boundary between two substances. There are many questions based on critical angle. Class 10 Refraction of light important questions and answers will prepare you with the necessary knowledge.

Introduction

Refraction is a captivating phenomenon in the realm of optics and the behaviour of light. It occurs when light, which is composed of electromagnetic waves, changes its direction as it moves from one medium (such as air) into another medium (like water or glass). This change in direction happens because the speed of light differs in each medium. Refraction plays a fundamental role in a wide range of natural phenomena and everyday experiences, as well as in the design of optical instruments and devices.Moreover, refraction is a fundamental concept in meteorology and geology. It is the reason why the sky appears blue, why stars twinkle, and how we see objects under the water's surface. In essence, refraction is a phenomenon that shapes how we perceive the world, impacts the design of countless optical instruments, and continues to be a source of wonder and fascination in the field of science. These concepts are crucial when studying refraction of light class 10 ICSE  important questions. 

What is the Refraction of light?

Refraction is the bending of light  as it passes from one transparent substance into another. This bending by refraction makes it possible for us to have lenses, magnifying glasses, prisms and rainbows. Consider refraction of light class 10 ICSE questions.

Class 10 Refraction of light Important Questions and Answers

Q1 : Select the correct reason why diamond appears to sparkle in the dark :

Options

(a) It has a low critical angle of 24^o
(b) Due to the light getting entrapped inside the diamond as a result of successive total internal reflection.
(c) Due to refraction of light
(d)  both (a) and (b)

Ans. (d) both (a) and (b)

Explanation:
Refractive index is quite high in diamond. This characteristic explains why diamonds sparkle. The diamond crystal sparkles because light penetrates it and is reflected numerous times internally.

Q2. When a light ray enters from one optical medium to another and bends towards the normal then :

Options

(a) Angle of incidence is less than angle of refraction
(b) it is travelling from optically denser medium to optically rarer medium
(c)  it is travelling from optically rarer medium to a optically denser medium
(d) Speed of light remains unchanged.

Ans. (c) it is travelling from optically rarer medium to a optically denser medium
Explanation:
When a light ray enters from one optical medium to another and bends towards the normal then speed of light decreases as it travels from rarer to denser medium.

Q3.  The wave lengths for the light of red and blue colours are nearly 7.8 × 10^{– 7} m and 4.8 × 10^{– 7} m respectively.
(i) Which colour has the greater speed in a vacuum?
(ii) Which colour has a greater speed in glass?

Explanation:
The wave lengths for the light of red and blue colours are nearly 7.8 × 10^{– 7} m and 4.8 × 10^{– 7} m respectively.
(i) Both colours of light have same speed in vacuum.
(ii) In glass, speed of red light is more than that of blue light.

Q4. Why do the faces of persons sitting around camp fire appear to shimmer?

Explanation:
The rays coming from the face of a person, sitting across the camp fire, suffer refraction on passing through hot air. Thus, we see an apparent image of the person. Since hot air is in motion, therefore, its optical density changes, which in turn shifts the image rapidly. This rapidly shifting image gives a shimmering effect.

Q5. A biconvex lens made of a transparent material of refractive index 1.25 is immersed in water of refractive index 1.33. Will the lens behave as a converging or a diverging lens? Justify your answer.

Explanation:
Generally, a biconvex lens acts as a converging lens in air because the refractive index of air is less than that of the material of the lens. The refractive index of water (1.33) is more than the refractive index of the material of the lens (1.25). So, on immersing in water it will behave as a diverging lens.

ICSE Class 10 Physics Chapter wise Important Questions

Conclusion

Refraction is a fundamental phenomenon in optics that occurs when light passes through a boundary between two different transparent materials, such as air and glass or water. Key points to remember about refraction include:Refraction is the bending of light as it passes from one medium to another with a different optical density. . For those looking for extra practice and a better grasp of the chapter's concepts, oswal.io provides a wide range refraction of light class 10 ICSE question, allowing for a more in-depth comprehension of the subject matter

Frequently Asked Questions

Q1 : What is refraction of light?

Ans:  Refraction is the bending of light as it passes from one transparent medium into another, caused by a change in the speed of light. It is a fundamental phenomenon in optics.Refraction is primarily caused by the change in the speed of light when it transitions from one medium to another with a different refractive index.

Q2 : Can refraction create optical illusions?

Ans:  Yes, refraction can create optical illusions. For example, it can cause objects to appear bent or distorted when viewed through water, and it is responsible for the formation of rainbows.

Q3 : How does refraction relate to the mirage effect?

Ans: The mirage effect is caused by the bending of light due to temperature gradients in the atmosphere. It creates optical illusions, such as the appearance of water on a hot road, and is a result of refraction.

Q4 : How does the refractive index of a material affect the degree of refraction?

Ans:  The refractive index of a material determines the extent to which light is bent when it passes through that material. Materials with higher refractive indices cause more significant refraction.

Q5 : Are there any situations where refraction is not observed?

Ans: Refraction occurs whenever light passes from one medium to another with a different refractive index. In situations where the two materials have nearly identical refractive indices, the bending of light may be minimal and less noticeable.