Question

A current of 10 A is established in a long wire along positive Z-axis. Find the magnetic field B at the point (1m, 0,0):-

• A. $1\mu T$ along the Y -ve direction
• B. $2\mu T$ along the Y +ve direction
• C. $1\mu T$ along the X -ve direction
• D. $2\mu T$ along the X +ve direction

Answer 1

The correct option is B $2\mu T$ along the Y +ve direction

Given that,
current $i=10A$

$r=1m$

Now, the magnetic field

$B=\frac{{\mu }_{0}2i}{4\pi }$

$B={10}^{-7}\times 20$

$B=2\times {10}^{-6}T$

$B=2\mu T$

Hence, the magnetic field is $2\mu T$ along $Y^{+}$ direction