A converging lens of focal length 15cm is used to obtain a real image magnified (1frac{1}{2}) times. Calculate the distance of the image from the lens?
-
A.
37.5cm -
B.
22.5cm -
C.
15cm -
D.
7.5cm -
E.
3.3cm
Correct Answer: Option A
Explanation
If u=x, v = (1frac{1}{2}x Rightarrow if u= 2x,v=3x\
frac{1}{f}=frac{1}{u}+frac{1}{v}; frac{1}{15}=frac{1}{2x}+frac{1}{3x} times frac{5}{6}\
X=frac{75}{76}=12.5, v=3x=12.5times 3=37.5)