Question

(iii) What is the 'focal length of a :
(a) concave mirror (b) convex lens,please tell me the correct answer only​

Answer 1

Answer:

THE focal length of a concave mirror is always negative and of convex lens is positive

Answer 2

Answer:

• Focal Length - The distance between the pole P of the concave mirror and the focus F is the focal length of the concave mirror. Thus, the focal length of a concave mirror can be estimated by obtaining a 'Real image' of a distant object at its focus.

• f, the focal length, is positive for a concave mirror, and negative for a convex mirror. When the image distance is positive, the image is on the same side of the mirror as the object, and it is real and inverted. When the image distance is negative, the image is behind the mirror, so the image is virtual and upright.