To obtain a magnification of 2.5, how far should an objec...
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?
0.13m
0.25m
0.28m
0.50m
Correct answer is C
v = 2.5u
F = uvu+v
0.2 = u×2.5uu+2.5u
u = 0.28m