GITAM, Department of Engineering Physics

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Magnetic Field of Current Loop

Electric current in a circular loop creates a magnetic field which is more concentrated in the center of the loop than outside the loop. Stacking multiple loops concentrates the field even more into what is called a solenoid.

Examining the direction of the magnetic field produced by a current-carrying segment of wire shows that all parts of the loop contribute magnetic field in the same direction inside the loop.

Field at Center of Current Loop

The form of the magnetic field from a current element in the Biot-Savart law becomes which in this case simplifies greatly because the angle =90 ° for all points along the path and the distance to the field point is constant. The integral becomes

Field on Axis of Current Loop

 

 

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