Students use an optical bench setup to explore how the focal length of a lens affects the distance . Keeping the object distance constant, if the students replace their first lens with a new lens having a longer focal length, how would this new lens affect the image distance?

a)

The image distance will be shorter because the longer focal length will magnify the image so it will appear closer

b)

The image distance will not change because the candle did not move

c)

The image distance will be longer because the focal length is related to both the object and image distance.

d)

The image distance will be longer because the focal length will cause the image to be very small so it will appear farther