(a) Where should a pin be placed on the optical axis such that its image is formed at the same place?
Given constants:
3. Stick a pin there
The convex surface of a thin concavo-convex lens of glass of refractive index 1.5 has a radius of curvature 20cm. The concave surface has a radius of curvature 60cm. The convex side is silvered and placed on a horizontal surface.