An object is located 3 cm in front of a converging lens of focal length 2 cm.A diverging lens of -6 cm focal length is placed 3 cm on the other side of the converging lens.What is the final image distance with respect to the diverging lens?
A)$\infty$
B)2 cm
C)-2 cm
D)6 cm
E)-6 cm

Question

Quizplus · Accepted Answer

Using the thin lens formula, we can find the image distance with respect to the converging lens:
1/f_total = 1/f1 + 1/f2 - d/f1f2
1/f_total = 1/2 + (-1/6) - (3/12)
1/f_total = 1/3
f_total = 3 cm
Now using the formula for image distance with respect to the diverging lens: 
1/s2 + 1/f2 = 1/f_total
1/s2 + 1/-6 = 1/3
1/s2 = 1/6 - 1/3
1/s2 = -1/6
s2 = -6 cm

Therefore, the final image distance with respect to the diverging lens is -6 cm.

An Object Is Located 3 Cm in Front of a Converging