An object is placed 4 cm in front of a concave lens of focal length 3 cm. Using the lens equation, find where the image will form and state whether it is a real or virtual image.

Answer 1

Learn the lens equation and apply it.

1/do + 1/di = 1/f

do is the object distance = 4 cm
di is the image distance
f is the focal length = 3 cm

If di is positive, the image is real.