An equiconvex lens of refractive index μ and radius of curvature R has its one surface silvered. A point source O is placed before the silvered lens so that its image is coincident with it, the distance of the object from the lens is :

Question

G1 Physics · Accepted Answer

Derived solution: Step 1: Use the thin-lens formula 1/f = 1/v - 1/u with m = v/u. For lens material/medium changes use the lens-maker relation with the relative refractive index; powers of thin lenses in contact add. Step 2: Substitute the values given in the question and apply the geometry/sign convention shown. Step 3: On simplification the result is R/(2μ - 1). Therefore the correct option is C.