PHY 122 — Electricity & Magnetism
Course Description
Second course in a three-semester sequence for students in physics, the physical sciences, or engineering. Covers electrostatics, electrical potential, capacitors, electric fields in matter, circuits, magnetostatics, magnetic fields in matter, induction, A.C. circuits, and electromagnetic waves. Calculus is used throughout.
Location & Time
Labs are held in B&L 268.
- Afternoon: 2:00 PM – 4:40 PM
- Evening: 4:50 PM – 7:30 PM
- Night: 7:40 PM – 10:20 PM
Statistics & Error Analysis
Prior to the first lab, go through the statistics & error analysis tutorial. Print out the accompanying document, and go through the examples.
Labs
Lab 1 — Coulomb's Law
Verify Coulomb's Law by measuring the electrostatic force between two charged spheres as a function of their separation and charge. Use log-log analysis to confirm the inverse-square dependence and determine the proportionality constant.
Lab 2 — Electrostatic Potential
Use a mechanically-balanced cylindrical capacitor to measure an absolute voltage by two independent methods: a displacement method based on the principle of virtual work, and a null method using calibrated masses. Map equipotential surfaces for two electrode configurations on resistive graphite paper and draw the corresponding electric field lines.
Lab 3 — Electron Beams
Inject an electron beam into a uniform magnetic field produced by a pair of Helmholtz coils and observe the resulting circular trajectory due to the Lorentz force. Use the measured radius of curvature and the known field strength to determine e/mₑ, the charge-to-mass ratio of the electron.
Lab 4 — Superconductivity and Ohm's Law
Observe the Meissner Effect by levitating a magnet above a high-temperature superconductor cooled in liquid nitrogen, demonstrating the expulsion of magnetic flux below the critical temperature. In the second part, build and measure simple DC resistive circuits to verify Ohm's Law and explore series and parallel resistance combinations.
Lab 5 — Electronic Circuits
Use an oscilloscope to study RC circuits, measuring capacitance from the charging and discharging time constant of a capacitor. Then assemble a resonant RLC circuit and identify the resonance frequency as a function of inductance and capacitance.