Magnetism

• magnetic field of solenoid (at centre) and toroid is u0nI
• coaxial cable has a inner central wire and outer cylindrical conduction wires with equal currents flowing in opposite direction. This makes the outer magnetic field zero.
• just as angular momentum of electron is quantized it's magnetic moment u = eL/2m is also quantized. the basic value u=eh/4(pi)m is called Bohr's magneton