Question:
The separation between the objective and the eyepiece of a compound microscope can be adjusted between $9.8 \mathrm{~cm}$ to $11 ' 8 \mathrm{~cm}$. If the focal lengths of the objective and the eyepiece are 1 ' $0 \mathrm{~cm}$ and $6 \mathrm{~cm}$ respectively, find the range of the magnifying power if the image is always needed at $24 \mathrm{~cm}$ from the eye.
Solution:
