The focal lengths of the objective and eyepiece of a telescope are 60 cm and 5 cm respectively. Find as magnifying power (P) for normal adjustment and when the image forms at near point.

Explanation

1. Magnifying power for normal adjustment = `-(f_(o))/(f_(e))=(-60)/5=-12`
2. Magnifying power for image at near point = `-(f_(o))/(f_(e))[1+f_(e)/D]=-60/5[1+5/25]=-14.4`