Question

A student has to determine the focal length of a concave mirror by obtaining the image of a distant object on a screen. For getting best result he should focus

(A) a distant tree or an electric pole

(B) a well-illuminated distant building

(C) well-lit grills of the nearest window

(D) a burning candle laced at the distant edge of the laboratory table

Answer 1

In order to determine the focal length of a concave mirror, the student should focus on a distant tree or an electric pole.

The Correct Answer is A