An object is placed 10cm from a converging lens of foal length 15cm. Calculate the magnification of the image formed
3.0
1.5
0.6
0.3
Correct answer is C
* produces a virtual image when object distance(u) is less than its focal length(f).
\(\frac{1}{f} = \frac{1}{u} - \frac{1}{v}\)
\(\frac{1}{v} = \frac{1}{f} + \frac{1}{u}\)
\(\frac{1}{15} + \frac{1}{10} = \frac{2 + 3}{30}\)
\(\frac{1}{v} = \frac{5}{30}\)
v = 6.0 cm
but m = \(\frac{v}{u} = \frac{6}{10} = 0.6\)
Note that the negative sign only shows the placement of the image. It has no effect on the magnification basically.