Question

difference between covex and clcave lens

Answer 1

concave lens are thinnest at the centre and become thicker and thicker on going to edges

convex lens are thickest at the centre and become thinner and thinner going to edges

Answer 2

Convex lens forms real and inverted images and sometimes virtual.
Concave lens forms virtual images.
Convex lens is a converging lens and concave is diverging.