Chapter 30, Problem 9A

To determine

To explain: In a telescope, one looks at the image of an image.

Explanation of Solution

Introduction:

A telescope is an optical instrument which is used to see far away or distant objects. It uses two pieces of convex lens.

A telescope consists of two lenses, the first one called objective lens and the second one called eyepiece. The real, inverted image formed by the objective lens is not projected on a screen but is projected towards another lens which acts as a magnifying glass to magnify the image. The eyepiece is placed in such a way that the image formed by the objective lens is within the focal length of eyepiece in order to obtain a virtual, inverted and magnified image of an image obtained by objective lens which serves as an object for eyepiece. In fact, the eyepiece forms image of an image formed by objective lens.

Conclusion:

Hence, in a telescope the image formed by objective lens serves as the object for eyepiece which further forms virtual, inverted and magnified image of that image. Thus, one looks at the image of an image in a telescope.