Question

Where should an object be placed for using a convex lens as magnifying glass ?

Answer 1

first of all magnifying means image size will be greater than object size .
so, m > +1
e.g., $\frac{h_i}{h_0}$> + 1 [ because m = v/u]
$h_i>h_0$

for convex lens , it is possible when ...
Object should be placed at a distance less than focal length order to use a convex lens as a magnifying glass.
see figure , for better understanding .

Answer 2

Can it be placed bw f and 2f