Question

A real image is formed by a convex lens, then it is put in contact with a concave lens and again a real image is formed. This image distance will

• A. Shift towards the lens system
• B. Shift away from the lens system
• C. Remain in its original position
• D. Shift top infinity

Answer 1

The correct option is B Shift away from the lens system

Net power will decrease or focal length will increase. For real image v is positive, u is negative and f is positive From lens formula (substituting all values with sign),
$\frac{1}{v}+\frac{1}{u}=\frac{1}{f}$
u is constant, f is increasing. So v will also increase.