A ray of light, after refraction through a convex lens emerges parallel to the principal axis.

(a) Draw a ray diagram to show it.

(b) The incident ray passes through a point F on the principal axis. Name the point F.

A beam of light incident on a convex lens parallel to its principal axis converges at a point F on the principal axis. Name the point F. Draw a ray diagram to show it.

The diagram below shows a lens as a combination of a glass slab and two prisms.

(i) Name the lens formed by the combination.

(ii) What is the line XX' called?

(iii) Complete the ray diagram and show the path of the incident ray AB after passing through the lens.

(iv) The final emergent ray will either meet XX' at a point or appear to come from a point on XX'. Label the point as F. What is this point called?

A parallel oblique beam of light falls on a

(i) convex lens,

(ii) concave lens.

Draw a diagram in each case to show the refraction of light through the lens.