1. Electricity and Magnetism
Physics 208
Dr. Tatiana Erukhimova
Lecture 28

3. Current carrying wires
1820 Hans Christian Oersted
Hans Christian Ørsted

4. Ampere’s Law
The field produced by an infinite wire

5. Problem 6
An infinitely long, hollow cylindrical wire has inner radius a and outer radius b. A current i is uniformly distributed over its cross-section. Find the magnetic field everywhere.

6. Biot-Savart Law
Infinitesimally small element of a current carrying wire produces an infinitesimally small magnetic field
is called permeability of free space
(Also called Ampere’s principle)

7. Problem 2 R 2R