Final answer:
For relaxed viewing, a microscope or telescope's eyepiece is adjusted to place the image at infinity, where the eye is most relaxed. The image is first magnified by the objective lens and then further enlarged by the eyepiece.
Step-by-step explanation:
For relaxed viewing with a microscope or a telescope, the eyepiece should be adjusted to place the image at infinity. This results in the viewer's eye being most relaxed, as the eye is naturally at rest when looking at distant objects. The objective lens creates an image that is slightly farther from its focal length, which then serves as the object for the eyepiece. By placing the first image closer to the eyepiece than its focal length, the eyepiece acts as a magnifying glass to further enlarge this image. Ultimately, the final image remains inverted and is positioned far from the observer, which is comfortable for viewing. The overall magnification of the system is the product of the magnifications from both the objective and the eyepiece lenses.