Question

A telescope has an objective of focal length $100\, cm$ and an eye-piece of focal length $5\, cm$. What is the magnifying power of the telescope when it is in normal adjustment ?

• A. 0.2
• B. 2
• C. 20
• D. 200

Answer 1

Answer: (C)

20

Answer 2

The magnifying power of the telescope in normal adjustment
$m=\frac{f_{o}}{f_{e}}=\frac{100}{5}=20$