Question

A long straight conductor carries a current of 5 amps. Find the magnetic field at a distance of 0.2 metre away from the wire. Given ${\mu }_0=4\pi \times {10}^{-7}wb{A}^{-1}{m}^{-1}$

• A. $5\times {10}^{-6}tesla$
• B. $0.5\times {10}^{-6}tesla$
• C. $5\times {10}^{-7}tesla$
• D. $2.5\times {10}^{-6}tesla$

Answer 1

The correct option is A $5\times {10}^{-6}tesla$

$I=5A$
$x=0.2m$
Magnetic field at a distance 0.2 m away from the wire.
$B=\frac{{\mu }_{0}I}{2\pi x}$
$=\frac{4\pi \times {10}^{-7}\times 5}{2\pi \times 0.2}$
$=10\times 5\times {10}^{-7}=5\times {10}^{-6}tesla$