When does a convex lens behave as a concave lens ?

When does a convex lens behave as a concave lens ?

Choose the following statement a True of False. a. The real image formed by a lens is always inverted. b. The image formed by a lens is always inverted. c. The image formed by a concave lens is always erect and diminished. d. An air bubble inside water acts like a concave lens. e. The distance between a real object and its real image formed by a single lens cannot be more than 4f. f. I an object is moved at a constant speed toward a convex lens from infinity to focus, then its image moves slower in the begninning and faster later on, away from the lens. g. The focal length of a glass (mu=1.5) lens is 10 cm in air. When it is completely immersed in water its focal length will become 40cm.

Air bubble in water behaves as a

A double convex air bubble in water will behave as

A double convex air bubble in water will behave as

An air bubble in water will act like a