JEE Main 2007 Physics question

Physics Ray Optics and Optical Instruments JEE Main 2007

Two lenses of power −15 D and +5 D are in contact with each other. The focal length of the combination is

(1)−20 cm
(2)−10 cmCorrect
(3)+20 cm
(4)+10 cm

Answer: (2)

Solution

D, so m cm, option (2).

Question ID VK-038919