Refraction by spherical lenses

Question 1 What is a lens?

Question 2 How many type of lens are them?

Question 3 What is a convex lens?

Question 4 What is a concave lens?

Question 5 Draw Bi-convex, plane-convex and concavo-convex lens?

Question 6 Draw Bi-concave, plane-concave and convexo-concave lens?

Refraction by Spherical Lenses

Lens is a transparent medium bounded by two refracting surfaces.

Types of lenses

(1) Convex or converging

(2) Concave or diverging

Convex Lens

A lens having both spherical surface or one spherical and other plane surface.

It is thick in the middle and thin at the edges.

They are of 3 types:

(a) Bi-convex

(b) Plane-convex

(c) Concavo-convex

Concave lens

(a) Bi-concave

(b) Plane-concave

(c) Convexo-Concave