Magnetic field due to current through 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 at every section of the circular loop by using the right-hand thumb rule.
3. However, 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 the same as a small ring looping around the periphery of the big ring.

The magnetic field created by a solenoid with a core and without a core

1. A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder is called a solenoid.
2. The pattern of the field is similar to a magnetic field around a bar magnet. One end of the solenoid behaves as a magnetic north pole, while the other behaves as the south pole.
3. 3. The field lines inside the solenoid are in the form of parallel straight lines. This indicates that the magnetic field is the same at all points inside the solenoid. That is, the field is uniform inside the solenoid.