An optical system consists of a thin convex lens of focal length `30 cm` and a plane mirror placed `15 cm` behind the lens. An object is placed `15 cm` in front of the lens. The distance of the final image from the object is

Options

A. 60 cm
B. 30 cm
C. 35 cm
D. 40 cm

Answer

A

Explanation

Foe lens
`u=-15f = 30`
`(1)/(V)-(1)/(60)=-(1)/(30)`
`(1)/(V)=(1)/(60)-(1)/(30)=(1-2)/(60)`
`V=-60- cm`

So, final image at 60 left of lens.
`287xx2=574`.