PHYS 102 Lecture Notes - Lecture 20: Electric Field, Solenoid, Provatas

• School: McGill University
• Department: Physics
• Course: PHYS 102
• Professor: Nick Provatas

Document Summary

Electric dc motor example: converts electrical energy to mechanical energy, direction of current reversed every half turn so full rotations are achieved. Example 8 (dc motor) o: only counterclockwise in 1 and 3 ; current has to be reversed in 3 to continue rotating counterclockwise with same forces in same directions as in. Other applications: speaker and microphone: converts electrical energy into mechanical energy o speaker/microphone: electrical signal to moving coil and moving coil to electrical signal (induction) respectively. Magnetic field due to long straight wire o: magnetic field due to the long straight wire forms concentric closed loop. Around the wire; wire has to be long compared to the field radius. Magnetic force between two parallel wires: two parallel wires with currents i1 and i2. Forces between two parallel wires o: f12 magnetic field is perpendicular to current at the location; f12 =