A convex spherical refracting surface separates a medium with index of refraction 2 from air.The image of an object outside the surface is real:
A)always
B)never
C)only if it is close to the surface
D)only if its distance from the surface is large compared to the radius of curvature
E)only if the radius of curvature is small

Question

Quizplus · Accepted Answer

The image formed by a convex spherical refracting surface can be real, virtual, or a point depending on the position of the object relative to the surface. If the object is outside the surface, the image can be real only if its distance from the surface is large compared to the radius of curvature. This is because for a real image to be formed, the incident rays of light from the object should converge after refraction, and then pass through the image point. This can only happen if the rays are refracted by a significant amount, which can only occur when the object is far away from the surface. Thus, the best choice is D.

A Convex Spherical Refracting Surface Separates a Medium with Index