Question

(b) Define power of a lens. What will be the effect on
focal length and power of lens when it is dipped in water​

Answer 1

✴️A glass lens when dipped in water will behave like a plane glass plate. Focal length of the lens will become infinity and it's power will become zero. Therefore, it no longer behaves as a lens. A concave lens of focal length 15 cm forms an image 10 cm from the lens.✴️

Answer 2

Answer:

• The power of a lens is defined as the reciprocal of the focal length. ... Converging (convex ) lenses have positive focal lengths, so they also have positive power values. Diverging (concave ) lenses have negative focal lengths, so they also have negative power values

• When a lens is immersed in water then focal length increase and focal length is inversely proportional to the angular magnification that's so the lens immersed in water the power decreases