Lens

Q.

Write four uses of convex and concave lenses in points.

Q.

Convex lens are the lens which are thicker in the middle and thinner at the edges.

1. False

2. True

Q.

Which of the following materials can be used to make a convex lens?

1. Transparent glass

2. Clear ice

3. Smooth steel

4. White cement

Q.

Suppose we wish to obtain the real image of a distant tree. Explain two possible ways in which we can do it.

Q. Give one example each of a real and a virtual image.

Q.

State whether the following statement is True or False.

A convex lens always produces a real image.

1. True
2. False

Q.

When the convex lens acts as a magnifying glass, the object is kept between the optical center of the lens, and what?

Q. What is the nature of lenses A and B respectively?

1. Converging, Diverging
2. Diverging, Converging
3. Converging, Converging
4. Diverging, Diverging

Q. Mention the type of image formed on a cinema screen.

Q. Mention the type of image formed on a cinema screen.

Q.

Himanshu has two lenses A and B. When he touches both the lenses he finds that A is thicker at the centre than at the edges and B is thinner at the centre as compared to its edges. He has to focus sunlight on a particular point. Which one of them can he use?

1. He should use lens B

2. He should use lens A

3. Neither of the lenses can be used

4. Insufficient information

Q. Explain why a real image can be projected on a screen but a virtual image cannot.

Q. Which of the following statements is correct about lenses A and B?

1. Lens A is a diverging lens
2. Lens B is a converging lens
3. Lens A can be used to focus sunlight at a point.
4. Lens B can be used to focus sunlight at a point.

Q.

Himanshu has two lenses A and B. When he touches both the lenses he finds that A is thicker at the centre than the edges and B is thinner at the centre as compared to its edges. He has to focus sunlight on a particular point. Which of the following statement is true?

1. He should use lens B

2. He should use lens A

3. Insufficient information

4. Neither of the lenses can be used

Q.

A convex lens always forms a virtual image.

1. True

2. False

Q. What are the characteristics of image formed by concave lens?
(3 marks)

Q. odd one out and give reason-virtual image, real image, erect image and laterally inverted image

Q.

Why are lenses used

Q. Which of the following can separate white light into its seven constituent colours?

1. Concave mirror
2. Convex mirror
3. Prism
4. Raindrop

Q.

Which of the following figure represents a convex lens?

1. 

2. None of these

3. 

4. 

Q. Choose the correct characteristics of the image.

1. D
2. C
3. B
4. A

Q.

Which of the following figure represents a convex lens?

1. 

2. 

3. None of these

4. 

Q.

Himanshu has two lenses A and B. When he touches both the lenses he finds that A is thicker at the centre than the edges and B are thinner at the centre as compared to its edges. He has to focus sunlight on a particular point. Which of the following statement is true?

1. He should use lens B

2. He should use lens A

3. Neither of the lenses can be used

4. Insufficient information

Q. Give one example each of a real and a virtual image.

Q. Choose the correct characteristics of the image.

1. A
2. B
3. C
4. D

Q.

An image formed by a concave lens is ___________, ___________ and _____________.

Q. What are the differences between a virtual image and a real image?​

Q.

Which lens is used in a magnifying glass?

1. Convex lens

2. Prism

3. Diverging lens

4. Concave lens

Q. Mention the type of image formed on a cinema screen.