A horizontal overhead power line carries a current of 90 A in east to west direction. What is the ma

Question

A horizontal overhead power line carries a current of 90 A in east to west direction. What is the magnitude and direction of magnetic field due to the current 1.5 m below the line?

Professor PC Thomas Classes · Answer

$B = \frac{\mu_0 I}{2\pi r} = \frac{4\pi 	imes 10^{-7} 	imes 90}{2\pi 	imes 1.5} = 1.2 	imes 10^{-5}	ext{ T}$. Using the Right-Hand Grip Rule, the field lines below the wire point towards the South.