Physics
State difference between a convex and a concave lens in their —
(a) appearance, and
(b) action on the incident light.
Answer
(a) The difference between a convex and a concave lens in terms of appearance is as follows —
| Convex lens | Concave lens |
|---|---|
| A convex lens is thick in the middle and thin at its periphery. | A concave lens is thin in the middle and thick at its periphery. |
| It bulges out in the middle. | It is bent inwards in the middle. |
(b) The difference between a convex and a concave lens in terms of action on the incident light is as follows —
| Convex lens | Concave lens |
|---|---|
| A convex lens converges the incident rays towards the principal axis. | A concave lens diverges the incident rays away from the principal axis. |
Related Questions
Complete the following sentences —
(a) If half part of a convex lens is covered, the focal length …………… change, but the intensity of image …………….
(b) The focal length of a thin convex lens is …………… than that of a thick convex lens.
(c) A tumbler filled with water behaves as a …………… lens.
Name the two kinds of lens? Draw diagrams to illustrate them.
Define the term principal axis of a lens.
Explain the optical centre of a lens with the help of proper diagram(s).