Advertisements
Advertisements
प्रश्न
What type of lenses are used in spectacles worn by an old lady for knitting?
Advertisements
उत्तर
A converging lens of suitable focal length is used in the spectacles worn by an old lady for knitting.
APPEARS IN
संबंधित प्रश्न
Explain optical centre of a lens with the help of proper diagram(s).
In the diagram below, XX’ represents the principal axis, O the optical centre and F the focus of the lens. Complete the path of rays A and B as they emerge out of the lens.
![]() |
![]() |
| (a) | (b) |
Distinguish between a real and a virtual image.
Study the diagram shown in Fig. 5.56
Complete the diagram to show the formation of image A’B’ of the object AB of same size.

Study the diagram shown in Fig. 5.56
Where is the image formed?

State the condition of the following:
A lens has both its focal lengths equal.
Complete the following diagram and state what happens to the ray of light after refraction through the lens.

Complete the following diagram and state what happens to the ray of light after refraction through the lens.

In the following diagram, L1 and L2 are the two convex lense placed at separation equal to the sum of focal lengths of the two lenses. A and B are the two rays of light incident on the lens L1. Complete the path of rays till they emerge out of the lens L2.

What principles have you used in completing the diagram?


