SAT Subject Physics Practice Question 444: Answer and Explanation
5. A light ray is moving parallel to the principal axis of a concave mirror, which it strikes. How will the light ray be reflected?
A. Back upon itself
B. Through the focal point
C. Through the radius of curvature
D. Through a point equal to 0.5f
E. Through a point equal to 2r
Correct Answer: B
The correct answer is (B). A ray parallel to the central radius is reflected through the focal point.