A point source `S` is placed at distance of `15` cm from a converging lens of focal length `10` cm . Where should a (i) concave mirror (ii) convex mirror of focal length `12` cm be placed so that real image is formed on object itself.

Explanation

`u= 15cm f = + 10 cm`
`(1)/(v )- (1)/(u) = (1)/(f ) rArr (1)/( v) - (1)/((-15)) = (1)/( 10) rArr v= 30 cm`
`(i) x= v + 2f rArr 30 + 2 xx 12 54 cm`
`(ii) x= v - 2 f rArr 30 - 2 xx 12 = 6 cm`