Question

A lady cannot see objects closer than 40 cm from the left eye and/closer than 100 cm from the right eye. While on a mountaineering' trip, she is lost from her team. She tries to make an astronomical telscope/ from her reading glasses to look for her teammates. (a) Which glass should she use as the eyepiece ? (b) What magnification can she get with relaxed eye ?

Answer 1

The lady can not see objects closer than 40 cm from the left eye and 100 cm from the right eye.
For the left glass lens,

(a) For an astronomical telescope, the eye piece lens should have smaller focal length. So, she should use the right lens (f =100/3cm) as the eye piece lens.