A spherical mirror and a thin spherical lens have each a focal length of – 15 cm. The mirror and the lens are likely to be ……………. 

Correct option is  C) 2f

Correct option is  B) – 40 cm

Correct option is  B) double

Correct option is  A) 20 cm

Correct option is  C) 40 cm

i. For a concave mirror focal length is the distance at which parallel incident rays converge. For a convex mirror, it is the distance from where parallel rays appear to...

For a point object or for a small finite object, the focal length of a small spherical mirror is related to object distance and image distance as, \(\frac{1}{f}=\frac{1}{v}+\frac{1}{u}\)

Correct option is A) f

Correct option is B) 15 cm

Correct option is A) 10 cm