Question 1 Find the power of concave lens of focal length 2m? Question 2 Find the focal length of concave lens whose power is -2 D? Question 3 The power of lens is 2.5 D.What is the focal length and the type of lens? Question 4 A convex and concave lens of focal length 50 cm and 40 cm are combined together,what is the power of the combination? Question 5 What is … [Read more...] about Power and application of a lens