Under what condition a convex (or any coverging) lens behave as a diverging lens. Explain.

At what conditions , real gas will behave as an ideal gas. Explain in 8 sentences.

Under what conditions of temperature and pressure a real gas behaves like an ideak gas ?

A lens behaves as a converging lens in air (mu_alpha = 1) and diverging lens inwater (u_omega = 1.33) . The refractive index mu of the material of the lens is