NCERT Solutions for Class 7 Science Chapter 11 - Light

1. Fill in the blanks: 

a. An image that cannot be obtained on a screen is called ----------.

Ans: Virtual image.

b. The image formed by a concave ---------- is always virtual and smaller in size.

Ans: Mirror.

c. An image formed by a ------------- mirror is always of the same size as that of the object.

Ans: Plane.

d. An image that can be obtained on a screen is called a --------- image.

Ans: Real.

e. An image formed by a concave ---------------- cannot be obtained on a screen.

Ans: Lens.

2. Mark “T” if the statement is true and “F’ if it is false.

a. We can obtain an enlarged and erect image by a convex mirror.

Ans: F.

The convex mirror forms an erect and diminished image.

b. A concave lens always forms a real image.

Ans: F

Concave lenses form virtual, erect and diminished images.

c. We can obtain a real, enlarged and inverted image by a concave mirror.

Ans: T

d. A real image cannot be obtained on the screen. 

Ans: F

It is a virtual image that cannot be obtained on the screen.

e. A concave mirror always forms a real image.

Ans: F

Concave mirrors can also form virtual images.

3. Match the items given in Column I with one or more items in Column II. 

Ans: The table showing the matched answers is,

4. State the characteristic of the image formed by a plane mirror.

Ans: Characteristics of the image formed by a plane mirror are:

1. The image distance is equal to object distance. 

2. Image height is equal to object height. 

3. The image is virtual and erect.

5. Find out the letters of the English alphabet or any other language known to you in which the image formed in a plane mirror appears exactly like the letter itself. Discuss your findings.

Ans: A, H, O, T, U, V, W, X, Y are the letters in the English alphabet which form the same image as the letter is, as they are laterally symmetrical.

6. What is a virtual image? Give one situation where a virtual image is formed.

Ans: Virtual image: When light rays seem to originate at a spot but do not actually intersect, a virtual image is created. It is visible to human eyes. As a result, rear-view mirrors create virtual images.

The situations where a virtual image is formed:

1. It is formed when reflected rays appear to meet.

2. Such images cannot be obtained on the screen.

3. Virtual images are always formed in the plane mirror and convex mirror.

7. State the differences between a convex and a concave lens.

Ans: The difference between convex and concave lens is shown below:

8. Give one use of a concave and a convex mirror.

Ans: Use of the concave and convex mirror: 

1. Concave mirror – used as a reflector in a torch.

2. Convex mirror – used in vehicles as a rear-view mirror. 

9. Which type of lens always forms a real image?

Ans: Neither concave nor convex lens always form a real image. A convex lens forms both real and virtual images. A concave lens forms virtual, erect and diminished images.

10. Which type of lens always forms a virtual image?

Ans: The type of lens which always forms a virtual image is:

1. A concave lens always forms a virtual image. 

2. After the rays are refracted, they never converge and so there will be no real image.

Choose the Correct Option in Questions 11-13.

11. A virtual image larger than the object can be produced by a

• Concave lens 

• Concave mirror 

• Convex lens 

• Plane mirror

Ans: (b) Concave mirror. 

A concave mirror forms a virtual image larger than the object.

12.David is observing his image in a plane mirror. The distance between the mirror and his image is 4 m. if he moves 1m towards the mirror, then the distance between David and his image will be 

• 3 m 

• 5 m 

• 6 m 

• 8 m

Ans: (c) 6 m. 

In the above image, 

The distance between the mirror and the object is equal to the distance between the mirror and the image.

The distance between mirror and David image is 4m

When he moves 1m towards the mirror, then the distance is reduced as,

Distance between the mirror and the object is 4-1=3m.

Therefore, the distance between David and his image is 3+3=6m.

13. The rear-view mirror of a car is a plane mirror. A driver is reversing his car at a speed of 2 m/s. The driver sees in his rear-view mirror the image of a truck parked behind the car. The speed at which the image of the truck appears to approach the driver will be 

• 1 m/s 

• 2 m/s 

• 4 m/s 

• 8 m/s.

Ans: (c) 4 m/s.

In a plane mirror, the object and its image always remain at the same distance from the mirror. So, when the car reverses at a speed of 2m/s, then the image will also appear to move towards the driver.

Therefore, the speed at which the image of the truck appears to approach the driver will be 2+2=4m/s.

NCERT Class 7 Science Chapter 11 Light - Quick Overview of Detailed Structure of Topics

Important Points Covered in Class 7 Science Light

• Light is a form of energy that enables us to see objects when it gets reflected from them. Light can be detected through our eyes.

• Light travels along a straight line.

• There are two types of images i.e. real images and virtual images.

• The process of changing the path of light through a mirror or shiny object is called the reflection of light.

• There are two types of spherical mirrors i.e. convex mirrors and concave mirrors.

• Lenses are defined as transparent pieces of glass. Lenses are bounded by two spherical surfaces.

• When white light passes through a glass prism then white light gets split into seven colors. This phenomenon of splitting white light is called dispersion of light.

Benefits of Vedantu’s NCERT Science Light Class 7 Questions and Answers

• Vedantu's NCERT Science Light Class 7 Questions And Answers provides comprehensive explanations and detailed answers to all questions, ensuring a solid grasp of the fundamental concepts of light.

• Class 7 Science Light explores various aspects of light, including reflection, refraction, and dispersion, elucidating the principles through practical examples and illustrations.

• Each solution is prepared by Vedantu’s Master Teachers to help students understand complex topics such as the formation of images by mirrors and lenses, the phenomenon of dispersion in prisms, and the functioning of the human eye.

• With step-by-step explanations, Vedantu's Light Chapter of Class 7 PDF facilitates conceptual clarity and promotes problem-solving skills development among students.

• By utilising Vedantu's Light Class 7 Questions And Answers, students can enhance their academic performance and develop confidence in solving questions related to the properties and behaviour of light.

Related Study Materials for Class 7 Science Chapter Light

For more insights, students can also download additional study materials provided by Vedantu for Chapter 11 of NCERT Science Class 7–

Conclusion

Vedantu’s NCERT Solutions for Class 7 Science Chapter 11 - Light offers a vital tool for students to understand light's principles. Focus on understanding the behaviour of light, reflection, and refraction. Previous year's question papers had around 5-7 questions related to this chapter. The solutions provide clear explanations, step-by-step guidance, and illustrative diagrams to aid comprehension. Using these resources effectively, students can strengthen their understanding of light phenomena and improve their exam performance. Mastering this chapter is essential for building a solid foundation in science and progressing confidently in their academic journey.

NCERT Solutions for Class 7 Science - Chapter-wise Link for FREE PDF

Additional Study Materials for Class 7 Science

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