A convex lens is placed in water, its focal length:AIncreasesBDecreasesCRemains the sameDDoubledAnswer: A. Increases Read Explanation: Convex lens convex lens is made by joining two spherical surfaces in such a way that it is thicker at the centre. Its thickness gradually reduces as we move towards the edge. A convex lens has the ability to converge the light rays to a point that are incident on it. it is called a converging lens. Read more in App