An astronomical telescope is made with lenses of focal lengths 80.0 and 2.00 cm. What is the barrel length of this telescope?
A) 80.0 cm
B) 82.0 cm
C) 78.0 cm
D) 105 cm
E) 127 cm

Question

Quizplus · Accepted Answer

The barrel length of a telescope is given by the sum of focal lengths of the lenses. Therefore, the barrel length of the telescope is 80.0 cm + 2.00 cm = 82.0 cm. Thus, the correct answer is choice (B).

An Astronomical Telescope Is Made with Lenses of Focal Lengths