To obtain a magnification of 2.5, how far should an object be placed from the pole of a thin converging lens of focal length 10.20m?
-
A.
0.13m -
B.
0.25m -
C.
0.28m -
D.
0.50m
Correct Answer: Option C
Explanation
v = 2.5u
F = (frac {uv}{u + v})
0.2 = (frac {u times 2.5u}{u + 2.5u})
u = 0.28m