Question

a) For convex lens, distance of real image from the optical centre is .........
b) Focal length of concave lens is ..........

• A. $a=positive,b=positive$
• B. $a=negative,b=negative$
• C. $a=positive,b=negative$
• D. $a=negative,b=positive$

Answer 1

The correct option is C $a=positive,b=negative$

$a)$ For convex lens, real image is formed on other side of the lens , thus $v$ is $positive$.

$b)$ Focal length of a concave lens is $negative.$

Answer-(C)