Question

A copper wire of diameter 1.6 mm carries a current of 20 A. Find the maximum magnitude of the magnetic field $\overrightarrow{B}$ due to this current.

• A. 5.0 mT
• B. 10 mT
• C. 15 mT
• D. 15.5 mT

Answer 1

The correct option is A 5.0 mT

Radius$=1.6/2=0.8mm=0.8\times {10}^{-3}m$

Current$=20A$

Maximum magnitude of the magnetic field$\overrightarrow{B}$

$B=IA(n=1)=20\times \pi (0.8\times {10}^{-3}{)}^2=5mT$