Two plano concave lenses of glass of refractive index 1.5 have radii of currature 20cm and 30cm respectively.They are placed in contact with the curved surface to wards each other and the space between them is filled with a liquid of refractive index `(5)/(2)`. The focal length of the combination is (in cm)

Two plano concave lenses of glass of refractive index 1.5 have radii of currature 20cm and 30cm respectively. They are placed in contact with the curved surface to wards each other and the space between them is filled with a liquid of refractive index 3. The focal length of the combination is (in cm) (A) 12 (B) 16 (C) -92

Two plano-concave lenses of glass of refractive index 1.5 have radii of curvature of 20 and 30 cm. They are placed in contact with curved surface towards each other and the space between them is filled with a liquid of refractive index (4)/(3) , find the focal length of the system.

Two plano-concave lenses (1 and 2) of glass of refractive index 1.5 have radii of curvature 25 cm and 20 cm. They are placed in contact with their curved surface towards each other and the space betweent hem is filled with liquid of refractive index (4)/(3) the the combination is

Two plano-concave lenses of glass of refractive 1.5 have radii of curvature of 20 and 30 cm. They are placed in contact with curved surface towards each other and the space between yhem is filled with a liquid of refractive index 2/3. Find the focal length of the system.

Two identical thin planoconvex glass lenses (refractive index 1.5) each having radius of curvature of 20cm are placed with their convex surfaces in contact at the centre. The intervening space is filled with oil of refractive index 1.7 . The focal length of the combination is

Two identical thin plano-convex glass lensses (refractive index 1.5) each having radius of curvature of 20 cm are jplaced with their convex suffaces in contact at the cenjtre. The intervening space is filled with oil of refractive index 1.7 The focal length of the combination is

A plano-concave lens is made of glass of refractive index 1.5 and the radius of curvature of its curved face is 100 cm. What is the power of the lens?