Current moves through a conductor at the speed of _____.
LIGHT: Approximately 186,000 miles per second.
When you connect a D-C ammeter into a circuit you should always observe the correct _____.
The law that defines the relationship between current, voltage and resistance is called _____ Law.
OHM'S LAW: If any two electrical characteristics are known, you can determine the third with Ohm's Law.
According to Ohm's Law, the current in any circuit is _____ proportional to the applied voltage.
Two meters that can measure electrical resistance are the _____ and _____.
OHMMETER & MEGOHMMETER: The ohmmeter measures circuit resistance; the megohmmeter measures the high resistance of insulation.
A material that gives up free electrons and offers only slight opposition to current flow.
Electrons in the outer orbits of an atom that can easily be forced out of their orbits.
A material that does not give up free electrons easily and offers opposition to current flow.
An insulation-resistance tester. Consisting of a high-range ohmmeter and a high-voltage generator.
The basic unit of resistance measure. One ohm is equal to the resistance that allows 1 ampere of current to flow when an emf of 1 volt is applied.
The term most frequently used to express the difference of potential between two charges or between two points of a circuit.
A meter that is connected across the line to measure the potential difference (voltage) between two points.
How should a voltmeter be connected in a circuit to measure voltage?
Across or in parallel with the potential points being measured.
Without a given potential, how do free electrons in a conductor constantly move?
From negative to positive.
The property of a circuit which limits, opposes or resists the flow of electricity through it.
The resistance of a conductor is measured in a unit called...
OHM: Named after the German physicist and mathematician George Simon Ohm.
When the current (I) and resistance (R) are known, the voltage (E) can be found by the formula.
E = I x R
When two points that have an electrical potential difference are joined by a conductor, _____ _____ results.
The terms voltage and potential are both used to indicate the electrical _____ in a system.
In an electrical system, the potential is provided by a storage _____, a mechanically driven _____, or a dry cell.
An electrical current is produced when an applied voltage sets the free _____ of a material in motion.
Materials that have few free electrons are called _____.
INSULATORS: Mica, porcelain, glass, bakelite and silicone are good insulating materials.
If a battery is connected to teh two ends of a wire, the electrons movement in the wire is toward the _____ battery terminal.