Question

The magnifying power of a compound microscope increases when

• A. The focal length of objective lens is increased and that of eye lens is decreased
• B. The focal length of eye lens is increased and that of objective lens is decreased
• C. Focal lengths of both objective and eye-piece are increased
• D. Focal lengths of both objective and eye-piece are decreased

Answer 1

Answer: (D)

Focal lengths of both objective and eye-piece are decreased

Answer 2

$m \propto \frac{1}{f_{o}f_{e}}$