Advertisements
Advertisements
Question
The diagram showed a lens as a combination of one glass block and two prisms. Complete the ray diagram and show the part of the incident ray AB after passing through the lens.
(i) Name of the lens formed by the combination.
(ii) What is the line XX’ called?
(iii) Mark the focus F.

Advertisements
Solution
The completed ray diagram is shown.

(i) The lens formed by the combination is the convex lens.
(ii) The line XX’ is called the principal axis.
(iii) The focus has been marked by the letter F in the diagram.
RELATED QUESTIONS
What is a lens?
The diagram below shows a lens as a combination of a glass slab and two prisms.
- Name the lens formed by the combination.
- What is the line XX’ called?
- Complete the path of the incident ray AB after passing through the lens.
- The final emergent ray either meets XX’ at a point or appears to come from a point on XX’. Label it as F. What is this point called?

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) |
State the condition of the following:
A ray passes undeviated through the lens.
In the following diagram the object and the image formed by the respective lenses are shown. Complete the ray diagram, and locate the focus. Find the focal length of the lens.

Make the correct choices in the following items:
lf the image can be focused on a screen it must be
State the nature and position of the object on the principal axis to obtain a real and magnified image.
Complete the following diagram and state what happens to the ray of light after refraction through the lens.



