Problem 10.13. A converging lens of 4 dioptres is combined with a diverging lens of −2 dioptres. Find the power and focal length of the combination? Geometrical Optics problem 13. Sindh Textbook Board (stb) problems

Problem 10.13. A converging lens of 4 dioptres is combined with a diverging lens of −2 dioptres. Find the power and focal length of the combination?