Question

The magnification of an image by a convex lens is positive only when the project is placed:

• A. at its focus $F$
• B. between $F$ and $2F$
• C. at $2F$
• D. between $F$ and optical centre
• E. beyond $2F$

Answer 1

The correct option is D between $F$ and optical centre

The magnification of an image by convex lens is positive only when the object is placed between focal point(F) and optical centre because Image formed by the convex lens for this location of the object is virtual and magnified and for real image $m=-$ve.
For virtual image, $m=+$ve.