A convex lens, of focal length 25 cm, and a concave mirror, of radius of curvature 20 cm. are placed co-axially 4 cm aprat from each other. An incident beam, parallel to the principal axis, is incident on the convex lens. Find the position and nature of the image formed by this combination.

Explanation

For image `l_1` :
` u=-prop " "u=-15 cm`
` (1)/(upsilon)-(1)/(u)=(1)/(f) " " (1)/(upsilon)+(1)/(u)=(1)/(f)`
` rArr upsilon =25 cm " "(1)/(upsilon)=(1)/(f)-(1)/(u)=(-1)/(10)+(1)/(15)`
`rArr upsilon =-30 cm`
Real image on same side of mirror.