Current & Circuits
The study of charges that are moving.
Electrodynamics
Current that keeps the same direction.
Direct current
A material’s opposition to current.
Resistance
How fast electrical energy is transferred.
Power
Parts lined up on one single path.
A series circuit
How much charge passes a point each second.
Current
Current that keeps reversing direction.
Alternating current
Voltage equals current times this.
Resistance
What the power company actually bills you for.
Energy
Parts that give current more than one path.
A parallel circuit
The unit of current.
The ampere
Small electronics such as a phone or Walkman use this.
Direct current
A material whose V-versus-I graph is a straight line.
Ohmic
The usual unit on a household electric meter.
The kilowatt-hour
In series, the current through each resistor is this.
Equal
Conventional arrows are drawn as if this kind of charge were flowing.
Positive
A wall outlet supplies this.
Alternating current
A part that lets current through easily one way and blocks it the other.
A diode
The zigzag symbol on a circuit drawing.
A resistor
In parallel, the voltage across each branch is this.
Equal
A complete loop from one battery terminal back to the other.
A closed circuit
A wrench across both terminals dumps the battery at once.
A short circuit
Raising a metal wire’s temperature does this to resistance.
Raises it
A drawing that uses symbols for battery, bulb, and wires.
A circuit diagram
One dead bulb kills a whole cheap light string because the string is this.
Series