Presentation on theme: "Start EM Ch.5: Magnetostatics finish Modern Physics Ch.7: J=L+S Methods of Math. Physics, Thus. 24 Feb. 2011, E.J. Zita Magnetostatics: Lorentz Force and."— Presentation transcript:
Start EM Ch.5: Magnetostatics finish Modern Physics Ch.7: J=L+S Methods of Math. Physics, Thus. 24 Feb. 2011, E.J. Zita Magnetostatics: Lorentz Force and Biot-Savart Law Divergence and Curl of B; Ampere’s Law Modern Physics Spin, Energy levels, Zeeman effect Fine structure, Bohr magneton, J=L+S
Ex.5.2: Cycloid motion: B=Bx, E=Ez, find particle motion if it starts from rest at the origin. 1. Draw. 2. Qualitative analysis. 3. Quantitative analysis.
Ex.5.4: (a) A current I is uniformly distributed over a wire of circular cross section with radius a. Find J.
Ex.5 (b) Suppose the current density in the wire is proportional to the distance from the axis: J=ks (for some constant k). Find the total current in the wire.
History of atomic models: Thomson discovered electron, invented plum-pudding model Rutherford observed nuclear scattering, invented orbital atom Bohr quantized angular momentum, improved H atom model. Bohr model explained observed H spectra, derived E n = E/n 2 and phenomenological Rydberg constant Quantum numbers n, l, m l (Zeeman effect) Solution to Schrödinger equation shows that E n = E/l(l+1) Pauli proposed spin (m s = ±1/2), and Dirac derived it Fine-structure splitting reveals spin quantum number