Question

Consider one point on an object near a lens.

a. What is the minimum number of rays needed to locate its image point? Explain.

b. How many rays from this point actually strike the lens and refract to the image point?

Short answer

(a) Rays needed to locate its image point is 2 rays

(b) Rays from this point actually strike the lens and refract to the image point is$\infty$rays.

Step-by-step solution

definition of lens:

They are divided into two types based on the shape and purpose of the lens. A concave lens is one that has at least one inwardly curved side. A biconcave lens is a concave lens with both sides curving inward.

Find number of rays(part a)

(a) To locate the image point, two rays must emerge from the point on the object and intersect at the image point. Because we know that light rays travel in straight lines and that two straight lines intersect uniquely, image formation is possible at the point of intersection.

find how many ray from this point(part b)

(b) An infinite number because every ray that hits the object point is reflected by it and strikes the lens, forming the image point.