1.

An object is placed at a distance of 30 cm from a concave mirror and its real image is formed at a distance of 30 cm from the mirror. The focal length of the mirror isA. 15 cmB. 45 cmC. 30 cmD. 20 cm

Answer» Correct Answer - A
(a) Given,u=-30 cm
v=-30 cm
Using relation, `(1)/(f)=(1)/(v)+(1)/(v)`
`(1)/(-30)+(1)/(-30)=(1)/(f)`
`therefore` Focal length of the mirror,f=-15 cm


Discussion

No Comment Found

Related InterviewSolutions