Key Terms
- ammeter
- instrument that measures current
- electromotive force (emf)
- energy produced per unit charge, drawn from a source that produces an electrical current
- equivalent resistance
- resistance of a combination of resistors; it can be thought of as the resistance of a single resistor that can replace a combination of resistors in a series and/or parallel circuit
- internal resistance
- amount of resistance to the flow of current within the voltage source
- junction rule
- sum of all currents entering a junction must equal the sum of all currents leaving the junction
- Kirchhoff’s rules
- set of two rules governing current and changes in potential in an electric circuit
- loop rule
- algebraic sum of changes in potential around any closed circuit path (loop) must be zero
- potential difference
- difference in electric potential between two points in an electric circuit, measured in volts
- potential drop
- loss of electric potential energy as a current travels across a resistor, wire, or other component
- RC circuit
- circuit that contains both a resistor and a capacitor
- shock hazard
- hazard in which an electric current passes through a person
- terminal voltage
- potential difference measured across the terminals of a source when there is no load attached
- thermal hazard
- hazard in which an excessive electric current causes undesired thermal effects
- three-wire system
- wiring system used at present for safety reasons, with live, neutral, and ground wires
- voltmeter
- instrument that measures voltage