Question -
Answer -
Note : Here wetook focal Length as 10 cm because if we take it as 9 cm then imagedistance will be zero ,which does not make any sense. (a) Area of each square, A =1 mm2
Object distance, u = −9 cm
Focal length of a converging lens, f = 9 cm
For image distance v, the lensformula can be written as:
Magnification, 
∴Area of each square in thevirtual image = (10)2A
= 102 × 1 = 100 mm2
= 1 cm2
(b) Magnifying power of the lens
(c) The magnification in (a) is not the same as themagnifying power in (b).
Themagnification magnitude is 
and the magnifying power is
Thetwo quantities will be equal when the image is formed at the near point (25cm).