Further, magnification of the objective
is given by   
O
O
O
O
1
|
|
(|
|/
)
1
v
u
u
f
=
−
which is large when  
|O
u|
 is slightly greater than fO The micro-
scope is used for viewing very close object So 
|O
u|
 is small, and
so is fO (e)
The image of the objective in the eye-piece is known as ‘eye-ring’