A 4cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 24 cm. the distance of the object from the lens is 16 cm. Find the position, size and nature of the image formed using the lens formula.

Explanation

The ray which stricks the mirror surface ncar the periphery are called marginal rays for comer lens. f = -24 cm. u= 16 cm using lens formula
`(1)/(f)= (1)/(v) =(1)/(u)`
`(1)/(24)= (1)/(v)- (1)/(-16)= (2-3)/(48)= (-1)/(48)`
V= -48 now `h_(1)= 4 cm`
so magnitication. `m= (h_(2))/(h_(1))= (v)/(u)`
`h_(2)= (v)/(u) xx h_(1)= (-48)/(-16) xx 4= 12 cm`
The image is formed at a distance of 48 cm from the optical focus of the lens on the same side of the object. This is indicated by the negative sign. Size of image is three times the size of objec i.e 12 cm.
Nature of image: Positive sign in the image height indicates that image is virtual and erect.