The flat face of a plano-convex lens of focal length 10 cm is silvered. A point source placed 30 cm in front of the curved surface will produce a

Options

A. real image 15 cm away from the lens
B. real image 6 cm away from the lens
C. virtual image 15 cm away from the lens
D. virtual image 6 cm away from the lens

Answer

B

Explanation

`(1)/(v)+(1)/(u)=(1)/(f)rArr (1)/(f)=(1)/("fm")-(2)/("fl")`
`(1)/(f)=(1)/(infty)-(2)/(10)=-(1)/(5) rArr f=-5`
`(1)/(v)+(1)/(-30)=-(1)/(5)`
`(1)/(v)-(1)/(5)+(1)/(30)=(-6+1)/(30)=(-5)/(30)rArr v=-6 cm`.