Question

why concave lens is called diverging lens

Answer 1

because the concave lens formed small image so we use concave leave ik

Answer 2

Concave lens is called diverging lens because concave lenses are thinner at the middle. Rays of light that pass through the lens are spread out. A concave lens is a diverging lens. when parallel rays of light pass through a concave lens the refracted rays diverge.