A coin is 12 cm in front of a converging lens with focal length of magnitude 4.0 cm.Where is the image?
A)8.0 cm behind the lens
B)6.0 cm in front of the lens
C)6.0 cm behind the lens
D)4.0 cm in front of the lens

Question

Quizplus · Accepted Answer

Using the thin lens equation:
1/f = 1/o + 1/i
where f is the focal length, o is the object distance, and i is the image distance.

Plugging in the values:
1/4 = 1/12 + 1/i

Solving for i:
i = 6 cm

Since the image distance is positive, the image is formed on the opposite side of the lens from the object, so it is 6 cm behind the lens. Therefore, the correct choice is C.

A Coin Is 12 Cm in Front of a Converging