question_answer

In an astronomical telescope in normal adjustment a straight black line of length L is drawn on inside part of objective lens. The eye-piece forms a real image of this line. The length of this image is I. The magnification of the telescope is                                    [NEET (Re) 2015]

A)  \[\frac{L}{l}+1\]          

B)       \[\frac{L}{l}-1\]

C)  \[\frac{L+1}{L-1}\]      

D)       \[\frac{L}{l}\]

Correct Answer: D

Solution :

We know, magnification of telescope, we have

Here