When a lens with a longer focal length is used, the screen must be moved away from the lens to maintain a sharp image.
If we replace the lens in the video with one that has a longer focal length, to keep the image sharp, the screen should be moved away from the lens. This is because, with a longer focal length, the distance from the lens to the image (also known as the image distance) increases to maintain the lens formula, which states that 1/f = 1/do + 1/di, where f is the focal length, do is the object distance, and di is the image distance. Therefore, if the lens' focal length increases, the image distance must increase as well, necessitating moving the screen further away to capture the focused image.
The complete question is- Part A
Part complete
Suppose we replace the lens in the video with one that has a longer focal length. To keep the image sharp, how should we move the screen?
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Suppose we replace the lens in the video with one that has a longer focal length. To keep the image sharp, how should we move the screen?
Away from the lens
Toward the lens
There is no need to move the screen.