(a) Area of each square , A=1mm2
Object distance u=−9cm
Focal length of the converging lens , f=10cm
For image distance v, the lens formula can be written as
1f=1v−1u
By putting the values we get v=−90cm
Now magnification,
m=uv=−60−9=10
∴ Area of each square in the virtual image = 102A=102×1=100mm2
(b) Magnifying power of the lens
d|u|=259=2.8
(c) The magnification in (a) is not same as the magnifying power in (b).
The ,magnification magnitude is
(|vu|) and the magnifying power is (d|u|)
The two quantities will be equal when the image is formed at the near point (25cm).