A lighted candle is placed d = 33 cm in front of a converging lens of focal leng
ID: 1776104 • Letter: A
Question
A lighted candle is placed d = 33 cm in front of a converging lens of focal length f1 = 14 cm, which in turn is 55 cm in front of another converging lens of focal length f2 = 12 cm.
A lighted candle is placed d 33 cm in front of a converging lens of focal length f1-14 cm, which in turn is 55 cm in front of another converging lens of focal length f2 12 cm. 12cm 55 cm Calculate the position and relative size of the final image position magnification cm beyond the second lens x size of the real objectExplanation / Answer
d = 33 cm
f1 = 14 cm
f2 = 12 cm
Now
1/s1 + 1/s1’ = 1/f1 ======> 1/33 + 1/s1’ = 1/14 =====> s1’ = 24.3 cm
m1 = -s1’/s1 = -24.3/33 = -0.736 (image inverted)
And
1/s2 + 1/s2’ = 1/f2 =======> 1/30.7 + 1/s2’ = 1/12 =====> s2’ = 19.7 cm from 2nd lens
M2 = -s2’/s2 = -19.7/30.7 = -0.642 (inverts first image)
Total magnification = mT = m1*m2 = 0.473
So final image will be real and erect since mT > 0.