the magnification of a telescope is changed by changing what?
my answer is the eyepiece
Correct.
Correct! The magnification of a telescope is indeed changed by changing the eyepiece. The eyepiece is the part of the telescope that you look through to observe the magnified image of an object.
To understand why changing the eyepiece affects the magnification, let's discuss a bit about how telescopes work. Telescopes typically consist of two main components: the objective lens (or primary mirror) and the eyepiece.
The objective lens (or primary mirror) is responsible for gathering light from the object you want to observe. It creates a real image of the object at its focal point. The size of this image is determined by the diameter of the objective lens or primary mirror.
The eyepiece's primary role is to magnify the image produced by the objective lens. It takes the real image created by the objective lens and further magnifies it to make it more visible and detailed to the observer.
The magnification power of the telescope is determined by the focal length of the objective lens divided by the focal length of the eyepiece. In other words, the larger the focal length of the eyepiece, the smaller the magnification, and vice versa. So, by changing the eyepiece, you can change the magnification of the telescope.
Typically, telescopes come with different eyepieces of varying focal lengths. For higher magnification, you can use an eyepiece with a shorter focal length, while for lower magnification, you can choose an eyepiece with a longer focal length.