Question

A plano-convex lens of focal length $20cm$ has its place side silvered :

• A. The radius of curvature of its curved surface of piano-convex lens is equal to half of radius of curvature of a surface of equi-convex lens of focal length $20cm$
• B. A object placed at $15cm$ on the axis on the convex side of silvered plano-convex lens gives rise to an image at a distance of $30cm$ from it
• C. An object placed at a distance of $20cm$ on the axis on the convex side of silvered plano-convex lens gives rise to an image at $40cm$ from it
• D. Silver plano-convex lens acts as a concave mirror of focal length $10cm$

Answer 1

Answer: (A), (B), (D)

The radius of curvature of its curved surface of piano-convex lens is equal to half of radius of curvature of a surface of equi-convex lens of focal length $20cm$
Silver plano-convex lens acts as a concave mirror of focal length $10cm$
A object placed at $15cm$ on the axis on the convex side of silvered plano-convex lens gives rise to an image at a distance of $30cm$ from it