·B=magnetic field strength (T)
·A=area perpendicular to the magnetic field (m²)
·Φ=magnetic flux (Wb)
·(∆Φ/∆t) is the derivative of Φ with respect to time.
·ε graph should be negative when Φ-t graph has +ve gradient
·ε graph should be positive when Φ-t graph has -ve gradient
Right Hand coil rule:
·thumb: direction of induced magnetic field
·fingers: direction of induced current
generators and alternators
·current (I) is the same through the whole circuit
·flow: from positive to negative terminal
·total resistance (RT) is the sum of individual resistances: R
·total voltage supplied to a circuit must be equal to the total voltage used around the circuit (sum of voltage drops): V
Transformers, comparing AC and DC
Transmission of power (Power systems)
·almost all wires have some resistance
·as electricity passes through the wires, it causes them to heat up, resulting in power loss, and a decrease in the voltage that is available at the load.
High voltage transmission
·we can reduce power loss by lowering the current in the line
·we can keep the same supply power by increasing the supply voltage
·this is done using transformers.
Generation and Transmission of electricity Cheat Sheet by cadmiumium
VCE unit 3 electricity