An astronomical telescope has an objective of diameter 20 cm with a focal length of 180 cm. The telescope is used with an eyepiece of focal length 3.0 cm. The magnifying power of the telescope is
A)360 X.
B)60 X.
C)540 X.
D)7 X.
E)180 X.

Question

Quizplus · Accepted Answer

The magnifying power of a telescope is given by the formula: Magnifying Power = Focal Length of Objective / Focal Length of Eyepiece. Here, it is 180 cm / 3 cm = 60 X.

An Astronomical Telescope Has an Objective of Diameter 20 Cm