1. 1 Everything Science www.everythingscience.co.za 11. Electrodynamics Physics Grade 12

2. 2 Everything Science www.everythingscience.co.za Electrical generators Electrical generators convert mechanical energy into electrical energy. There are two types of generators - AC and DC. An AC generator is also called an alternator. AC generator 3. 3 Everything Science www.everythingscience.co.za Electrical generators contd. DC generator 4. 4 Everything Science www.everythingscience.co.za Electric motors An electric motor is a device that converts electrical energy into mechanical energy. The Lorentz force is the force experienced by a moving charged particle in an electric and magnetic field. The magnetic component is: An electric motor works by using a source of emf to make a current flow in a loop of conductor such that the Lorentz force on opposite sides of the loop are in opposite directions which can cause the loop to rotate about a central axis. F=qvB 5. 5 Everything Science www.everythingscience.co.za Alternating current The root mean square (rms) value is the maximum value of the quantity can have divided by 2. RMS values are used for voltage and current when dealing with alternating current. The average power dissipated in a purely resistive circuit with alternating current is: Irms= Imax (2) V rms= V max (2) Pav=Irms V rms= 1 2 Imax V max 6. 6 Everything Science www.everythingscience.co.za For more practice see: everythingscience.co.za Shortcode: ESCQG 7. 6 Everything Science www.everythingscience.co.za For more practice see: everythingscience.co.za Shortcode: ESCQG