Question

Q3. Differentiate between
1. Concave lens and Convex lens
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Answer 1

A convex lens is a lens is a lence which have two spherical surfaces bulging outwards. It converges light rays and hence called as a converging lens. It's focal length is always positive.

A concave lens is a lens bounded by two spherical surfaces, curved inwards. It is thicker at the edges than at middle. It diverges light rays and hence called as a diverging lens. It's focal length is negative.