How can a convex lens behavae like a diverging lens?

Under what conditions a concave lens can behave as a converging lens?

Explain,why an air bubble inside a transparent liquid behaves like a diverging lens.

Can a convex (converging) lens behave as concave (diverging) lens in some situations? Give example?

A lens behaves as a converging lens in air and diverging lens in water.The refractive index of the material of the lens is

A convex lens made up of glass of refractive index 1.5 is dipped,in turn ,in medum B of refractive index 1.33. whether it will behave as a converging lens or a diverging lens?

A biconvex lens of a transparent material of refractive index 1.25 is immersed in water of refractive index 1.33 will the lens behave as a converging or a diverging lens?Give reason.

Can a convergent lens in one medium behave as a divergent lens in some other medium?

Why does a convex lens of glass mu=1.5 behave as a diverging lens when immersed in carbon disulphide of higher refractive index mu=1.65 ?