Question

Define optical centre of a lens.

Hint:

The optical centre is the point within a lens where light does not get refracted.

Answer 1

Step 1: Understanding optical centre.
The optical centre of a lens is the point within the lens at which a ray of light passing through it does not undergo any deviation. In other words, light that passes through the optical centre of the lens does not get refracted, and it continues its path without bending.
Step 2: Characteristics of the optical centre.
The optical centre is usually located at the intersection of the two principal planes of the lens, and it is the point where the two surfaces of the lens are symmetrically aligned.

Step 3: Conclusion.
In a convex or concave lens, the optical centre is the point where light passes through without deviation.