Biot-Savart Law-
Before you go through this article, make sure that you have gone through the previous article on Biot-Savart Law.
We have learnt-
- In 1820, Oersted discovered that a current carrying conductor produces a magnetic field around it.
- Biot-Savart law helps to calculate the magnetic field due to the current element of a thin wire.
- The magnetic field at any point due to the current element is given by-
In this article, we will learn about the magnetic field at the center of a circular current carrying loop.
Magnetic Field At The Center of Circular Current Carrying Loop-
Consider a circular loop of wire of radius R carrying current I. We wish to determine the magnetic field at its center.
The entire loop can be assumed to be made up of a large number of small current elements. We consider one such current element of the loop as shown-
Using Biot-Savart law, the magnitude of the magnetic field dB at the center O due to this current element is given by-
The net magnetic field due to all such current elements of the loop at center O is given by-
Thus, the net magnetic field at the center of a circular current carrying loop is given by-
If instead of a single loop, there is a coil of N turns all wound one over another, then-
Direction of Magnetic Field-
- The magnetic field lines due to a circular current carrying loop form closed loops.
- The field lines near the wire are almost concentric circles.
- As we move radially towards the center of the loop, the concentric circles become larger and larger i.e. the field lines become less and less curved.
- The lines at the center are almost straight, parallel and perpendicular to the plane of the loop.
- Thus, the magnetic field is uniform at the center of the loop.
- The direction of magnetic field lines is given by Right Hand Thumb Rule.
Right Hand Thumb Rule For Circular Loop
According to this rule, if the palm of right hand is curled around the circular loop such that fingers point in the direction of current, then the extended thumb gives the direction of magnetic field lines. |
The following diagram shows the pattern of magnetic field lines due to a circular current carrying loop-
If the circular current carrying loop lies in the plane of paper, then-
- For clockwise current, the direction of magnetic field at the center is into the plane of paper.
- For anticlockwise current, the direction of magnetic field at the center is out of the plane of paper.
MCQs Quiz-
MCQs Quiz
on Magnetic Field At Center of Circular Current Loop
Worksheet-
on Magnetic Field At Center of Circular Current Loop
Next Article-
Magnetic Field At The Center of Circular Current Carrying Arc
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