Question

A concave lense of refractive index 1.5 is immersed in a medium of refractive index 1.65. What is the narture of the lense

Answer 1

A concave lens with refractive index 1.5 (with respect to air) is a diverging lens when surrounded by air. When a ray of light is incident on the lens, when the lens is surrounded by air, the ray bends towards the normal as it is moving from a rarer to a denser medium