A converging lens is used to focus light from a small bulb onto a book.The lens has a focal length of 10.0 cm and is located 40.0 cm from the book.Determine the distance from the lens to the light bulb.
A)8.6 cm
B)13 cm
C)20 cm
D)30 cm
E)50 cm

Question

Quizplus · Accepted Answer

The lens equation is 1/f = 1/d_o + 1/d_i, where f is the focal length, d_o is the object distance, and d_i is the image distance. Given f = 10.0 cm and d_i = 40.0 cm (distance from lens to book), we solve for d_o: 1/10 = 1/d_o + 1/40. Solving for d_o gives d_o = 13 cm.

A Converging Lens Is Used to Focus Light from a Small