Question

What are concave and convex lens ?

Answer 1

Concave lenses are thinner at the middle. Rays of light that pass through the lens are spread out (they diverge). A concave lens is a diverging lens. When parallel rays of light pass through a concave lens the refracted rays diverge so that they appear to come from one point called the principal focus.


· In the convex lens, the curve is outward facing, whereas, in the concave lens, the curve faces inward. When the light rays pass through the convex lens, it converges the light rays and focuses on one point. On the other hand, when the light rays go through the concave lens, it diverges the beams, i.e. they spread out.

Answer 2

When a spherical mirror is cut symmetrically along the centre of the spherical mirror then two hemispherical mirrors are formed. If we polish the inner surface of the hemispherical mirrors then they become convex mirrors. If we polish the outer surface of the hemispherical mirrors then they become concave mirrors.

Hope this helps you!