What is Lens
It is a transparent glass
it is bound by 2 spherical surfaces
Hence, if 2 glass spheres are joined together, they form a lens
What are Different Types of lens
They are of 2 types
Concave Lens
It is thin in center but thicker at the edges
Convex Lens
It is thick in middle but thinner at the edges
Real life images of Concave and Convex Lens look like
Questions
NCERT Question 1 -
Which one of the following materials cannot be used to make a lens?
(a) Water (b) Glass (c) Plastic (d) Clay