A compound microscope has a barrel length of [tex]$L = 159.0 \text{ mm}$[/tex] and an objective with a 3.570 mm focal length. The total angular magnification of the microscope is -409.0.

Using the approximation that the barrel length is large relative to the focal lengths, determine the angular magnification [tex]M_c[/tex] of the eyepiece.

[tex]
M_{ e }=
[/tex]
[tex]\square[/tex]



Answer :

To determine the angular magnification [tex]\( M_c \)[/tex] of the eyepiece for a compound microscope, follow these steps:

1. Define the given parameters:
- The barrel length [tex]\( L \)[/tex] is 159.0 mm.
- The focal length of the objective lens [tex]\( f_{objective} \)[/tex] is 3.570 mm.
- The total angular magnification [tex]\( M_{total} \)[/tex] is -409.0.

2. Calculate the magnification of the objective lens [tex]\( M_o \)[/tex]:
The formula for the magnification of the objective lens is:
[tex]\[ M_o = -\frac{L}{f_{objective}} \][/tex]
Substituting the given values:
[tex]\[ M_o = -\frac{159.0 \text{ mm}}{3.570 \text{ mm}} = -44.537815126050425 \][/tex]

3. Calculate the magnification of the eyepiece [tex]\( M_c \)[/tex]:
The total magnification [tex]\( M_{total} \)[/tex] is the product of the magnifications of the objective and the eyepiece:
[tex]\[ M_{total} = M_o \times M_c \][/tex]
Solving for [tex]\( M_c \)[/tex]:
[tex]\[ M_c = \frac{M_{total}}{M_o} \][/tex]
Substituting the known values:
[tex]\[ M_c = \frac{-409.0}{-44.537815126050425} = 9.183207547169811 \][/tex]

So, the angular magnification [tex]\( M_c \)[/tex] of the eyepiece is approximately [tex]\( 9.183 \)[/tex].

Thus,
[tex]\[ M_e \approx 9.183 \][/tex]