A biconvex lens of focal length 15cm is in front of a plane mirror. The distance between the lens and the mirror is 10cm. A small object is kept at distance of 30cm from the lens. The final image is

Options

A. virtual and at a distance of 16 cm from the mirror
B. real and at a distance of 16 cm from the mirror
C. virtual and at a distance of 20 cm from the mirror
D. real and at a distance of 20 cm from the mirror

Answer

B

Explanation

`(1)/(v) + (1)/(30) = (1)/(15) imples (1)/(v) = (1)/(30) "and" (1)/(v) - (1)/(10) = (1)/(15)`
`implies (1)/(v) = (1)/(15) + (1)/(10) implies v = 6`