Four lenses of focal length ±5 cm and ±200 cm are available for making a telescope. To produce the largest magnification for making a telescope with the help of these lenses, the focal length of eye piece should be:

+5 cm

The correct answer is Option (4) → +5 cm

To produce the largest magnification in telescope,

Angular Magnification $M =-\frac{f_{objective}}{f_{eyepiece}}$

∴ $f_{objective}=+200cm$ (largest positive value)

$f_{eyepiece}=+5cm$ (smallest positive value)