Question

To determine focal length of a concave mirror a student obtains the image of a well lit distant object on a screen. To determine the focal length of the given concave mirror he needs to measure the distance between:

(A) mirror and the object

(B) mirror and the screen

(C) screen and the object

(D) screen and the object and also mirror and the screen

Answer 1

Focal length is the distance between the focus and the mirror. The image of the distant object forms at the focus of the mirror.

The Correct Answer is B