Question

An object is placed in front of a convex mirror at infinity. According to the New Cartesian Sign Convention, the sign of the focal length and the sign of the image distance in this case are respectively:

(a) +, -
(b) -,+
(c) -, -
(d) +,+​

Answer 1

the correct answer is (c) -, -.

Step-by-step explanation:

When an object is placed in front of a convex mirror at infinity, the image formed is a virtual image located at the focal point of the mirror.

According to the New Cartesian Sign Convention, the focal length of a convex mirror is negative. Therefore, the sign of the focal length in this case is "-".

Since the image is formed behind the mirror and is a virtual image, its distance from the mirror is negative. Therefore, the sign of the image distance in this case is also "-".

Therefore, the correct answer is (c) -, -.