A convex lens of focal length 30 cm forms an image of height 2 cm of an object placed at infinity. Now a concave lens of focal length 20 cm is placed at a distance of 26 cm to the side in which image is formed. The height of image formed by the combined system of the same object is
Answer & explanation
Correct answer: option 1
For concave lens,
f = -20 cm
u = +4 cm
$m=\frac{F}{u+F}=\frac{-20}{+4-20}=\frac{-20}{-16}=\frac{5}{4} $
$\frac{I}{O}=\frac{v}{4}=\frac{5}{4}$
I = +2.5 cm
∴ (a)