At great axial distances x from a current-carrying loop the magnetic field varies as A)x² B)x^-3 C)x^-2 D)x³ E)x^-1

Question

Quizplus · Accepted Answer

According to the formula for the magnetic field at an axial distance from a current-carrying loop, it varies as x*S1/(x^2 + r^2)^1/2. When x is much greater than r (the radius of the loop), x^2 >> r^2 and we can simplify the equation to x*S1/r. Therefore, the magnetic field varies as xS1/r at great axial distances. This matches option C: x^-2, where U1P1-2 represents 1/r.

At Great Axial Distances X from a Current-Carrying Loop the Magnetic