A lens with a negative focal length of -10.0 cm is on the same axis as a lens with a positive focal length of +20.0 cm as illustrated. The distance between the lenses is 20.0 cm. A real object 3.00 cm high is placed 20.0 cm to the left of the first lens. After the light has passed through both lenses, the final image is

Question

Quizplus · Accepted Answer

Using the thin lens equation for each lens, we can find that the image formed by the first lens is located 40 cm to the right of it and has a height of 6.00 cm. This image acts as the object for the second lens, which forms a final image that is located 40 cm to the left of it and has a height of 3.00 cm. Since the final image is located on the opposite side of the lens from the object, it is real. Since the final image is smaller than the object, it is also inverted, so the answer is D.

A Lens with a Negative Focal Length of -10