Magnetic Effects Of Current Question 45
Question: A circular coil of radius R carries an electric current. The magnetic field due to the coil at a point on the axis of the coil located at a distance r from the centre of the coil, such that r » R, varies as [EAMCET 1987; AIIMS 2004]
Options:
A) $ \frac{1}{r} $
B) $ \frac{1}{{{r}^{3/2}}} $
C) $ \frac{1}{r^{2}} $
D) $ \frac{1}{r^{3}} $
Show Answer
Answer:
Correct Answer: B
Solution:
$ B=\frac{{\mu_{o}}}{4\pi }.\frac{2\pi NiR^{2}}{r^{3}}\Rightarrow B\propto \frac{1}{r^{3}} $
BETA
