A point object is placed at the centre of a glass sphere of radius 6 cm and refractive index 1.5. The distance of the virtual image from the surface of the sphere is :-
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Question

A point object is placed at the centre of a glass sphere of radius 6 cm and refractive index 1.5. The distance of the virtual image from the surface of the sphere is :-

G1 Physics · Accepted Answer

Derived solution: Step 1: For paraxial refraction at a spherical surface use n₂/v - n₁/u = (n₂ - n₁)/R, applying the Cartesian sign convention at each surface. Step 2: Substitute the values given in the question and apply the geometry/sign convention shown. Step 3: On simplification the result is 6 cm. Therefore the correct option is C.