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

Answer:

A)Mirror and the object.

Answer 2

(B) mirror and the screen

Explanation:

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 the mirror and the screen.

Concave mirror is a spherical mirror in which the reflecting surface bulges inwards. A concave mirror is a converging mirror and the incident light rays are reflected inwards towards the focal point. So, these mirrors help focus light.