A 1.5 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 15 cm. Distance of object from the lens is 20 cm. Use lens formula to find the nature, position and size of the image.

Explanation

`h_(1)= +1.5 cm, f= +15 cm, u = -20 cm`
As we know, `(1)/(f)=(1)/(v)-(1)/(u)rArr(1)/(v)=(1)/(f)+(1)/(u)`
`(1)/(v)=(1)/((+15))+(1)/((-20))=(1)/(15)-(1)/(20)=+(1)/(60)" "therefore" "v = +60 cm`
Now, `(h_(2))/(h_(1))=(v)/(u) rArr h_(2) = (v xx h_(1))/(u)=(+60 xx 1.5)/(-20) = -4.5 cm`
Nature : Real and inverted.