Chapter 4: Moving Charges and Magnetism
- Magnetic field is the area around a magnet or a current-carrying conductor in which its magnetic influence can be felt. Tesla is the SI unit for it (T).
- Oersted demonstrated that the current-carrying conductor generates a magnetic field around it in an experiment.
- The Law of Biot-Savart: The magnetic field due to a small current-carrying element dl at any nearby point P is given by
A magnetic field in the center of a circular current-carrying conductor or coil.
Magnetic field in the semi-circular current-carrying conductor’s center.
- Magnetic field in the center of a circular current-carrying conductor arc with an angle of 0 at its center.
- Any point on the axis of a circular current-carrying conductor has a magnetic field.
Ampere’s Circuital Law
- Any closed loop’s line integral of the magnetic field B is equal to 0 times the total current I threading through the loop, i.e.
- Maxwell popularized the term “displacement current.”