# A telescope has an objective of focal length 50cm and an eyepiece of focal length 5cm. The least distance of distinct vision is 25cm. The telesc

41 views
in Physics
closed
A telescope has an objective of focal length 50cm and an eyepiece of focal length 5cm. The least distance of distinct vision is 25cm. The telescope is focused for distinct vision on a scale 2m away from the objective. Calculate (a) magnification produced and (b) separation between objective and eyepiece.

by (91.4k points)
selected

Given, f_0=50cm and f_e=5cm
For objective 1/v-1/-200=1/50
:. v_0=200/3cm
m_0=v_0/u_0=((200//3))/(-200)=-(1)/(3)
For eyepiece 1/-25-1/u_e=1/5
:. u_e=-25/6cm
and m_e=v_e/u_e=(-25)/-(25//6)=6
(a) Magnification, m=m_0xxm_e=-2
(b) Separation between objective and eyepiece,
L=v_0+|u_e|=200/3+25/6=425/6
=70.83cm