When an astronomical telescope is in normal adjustment, the focal length of the objective lens is 50cm and that of the eye piece is 5.0cm. What is the distance between the lenses?
A
10.0cm
B
30.0cm
C
45.0cm
D
55.0cm
E
250.0cm
Verified Correct Answer: D.
Physical Principles & Numerical Solution
An astronomical telescope is said to be in NORMAL adjustment when the distance between the objective lens and the eyepiece equals the sum of their focal lengths.
hence,
D = \(F_e\) + \(F_o\)
= 50cm + 5cm
= 55cm
Source: Myschool Past Questions Archive (Record #42841)