JEE Main & Advanced
Physics
Ray Optics
Question Bank
Self Evaluation Test - Ray Optics and Optical Instruments
question_answer
Two thin symmetrical lenses of different nature and of different material have equal radii of curvature R = 15 cm. The lenses are put close together and immersed in water \[(a=4/3).\] The focal length of the system in water is 30 cm. The difference between refractive indices of the two lenses is