Question

Explain with the help of a labeled diagram the distribution of magnetic field due to a current through a circular loop. Why is it that if a current-carrying coil has n turns the field produced at any point is n times as large as that produced by a single turn?

Answer 1

Part 1. Magnetic field:

1. It is a region around a magnetic material or a moving electric charge within the periphery of which the force of magnetism acts.
2. It is a force field that is created by moving electrical charges and magnetic dipoles and it exerts a force on other moving charges and magnetic dipoles.
3. The SI unit of field intensity of magnetic fields is Tesla (T).

Part 2. The magnetic field in a circular loop:

1. The magnetic field lines are concentric circles at every point of a current-carrying circular loop.
2. We can find the direction of the magnetic field of every section of the circular loop by using the right-hand thumb rule.
3. But the circular shape of the conductor means that field lines at different points of the loop appear to be making a ring around the periphery of the loop.
4. This is as same as a small ring looping around the periphery of the big ring.

Part 3. Effect of turns($n$):

1. The magnetic field increases if the number of coils increases.
2. Due to this, the strength of the magnetic field increases with the number of turns in a coil.
3. It happens because the current in each circular turn has the same direction and the field due to each turn adds up.
4. If there is a circular coil having $n$ turns, the field produced is $n$ times as large as that produced by a single turn.

Thus magnetic field intensity increases as the number of turns increases.