Appeared in: 2025 (3 sets)
A double-convex lens, made of glass of refractive index $1\cdot5$, has focal length $10\text{ cm}$. The radius of curvature of its each face, is :
(A) $10\text{ cm}$
(B) $15\text{ cm}$
(C) $20\text{ cm}$
(D) $40\text{ cm}$