Question

which lens is called as diverging lens

Answer 1

concave lens
✓✓✓✓✓✓✓✓✓✓

Answer 2

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.