Answer:
[tex]f_{e}[/tex] = 1.7 cm
Explanation:
The magnification of the compound microscope is given by the product of the magnification of each lens
M = M₀ [tex]m_{e}[/tex]
M = - L/f₀ 25/[tex]f_{e}[/tex]
Where f₀ and [tex]f_{e}[/tex] are the focal lengths of the lens and eyepiece, respectively, all values in centimeters
In this exercise they give us the magnification (M = 400X), the focal length of the lens (f₀ = 0.6 cm), the distance of the tube (L = 16 cm), let's look for the focal length of the eyepiece ([tex]f_{e}[/tex])
[tex]f_{e}[/tex] = - L / f₀ 25 / M
Let's calculate
[tex]f_{e}[/tex] = - 16 / 0.6 25 / (-400)
[tex]f_{e}[/tex] = 1.67 cm
The minus sign in the magnification is because the image is inverted.
[tex]f_{e}[/tex] = 1.7 cm