Question

In the normal adjustment of an astronomical telescope, the objective and eyepiece are 36 cm apart. If the magnifying power of the telescope is 8, find the focal lengths of the objective and eyepiece.

• A. \( F_o = 28 \, cm,\; F_e = 7 \, cm \)
• B. \( F_o = 28 \, cm,\; F_e = 4 \, cm \)
• C. \( F_o = 32 \, cm,\; F_e = 4 \, cm \)
• D. \( F_o = 4 \, cm,\; F_e = 32 \, cm \)

Hint:

For an astronomical telescope in normal adjustment, use \( F_o + F_e = \text{tube length} \) and \( M = \frac{F_o}{F_e} \).

Answer 1

The Correct Option is C