Electrical Power Flashcards
What are the four basic units of electricity?
Volts(V).
Resistance(R).
Current(I).
Power(P).
How is Resistance(R) Measured?
In the form of Ohms.
What is resistance(R)?
It is the opposition to the flow of current in a circuit.
Lower resistance allowsmore current.
A good fuse has low or almost no resistance.
What is voltage(V)?
The measure of work required to move a charge from one location to another.
A computer power supply typically produces several different voltages.
How is current measured?
In Amperes or Amps(A).
What is current(I)? How is it used in a computer?
It is a measure of the amount of electrons moving through a circuit per second.
Computer Power supplies deliver different amperages for each output voltage.
How is power(P) measured?
In the form of Watts(W).
How are computer power supplies rated?
In Watts(W).
What is wattage(W)?
A measure of the work required to move electrons through a circuit, multiplied by the number of electrons going through that circuit per second.
P=VI.
What is Ohms law?
A law that expresses how Voltage is equal to the current multiplied by the resistance?
V=IR
What is the small switch on the back of some power supplies known as?
The voltage switch selector.
What are power supplies with the switch known as?
Dual voltage power supplies.
How is the correct voltage setting determined?
It is determined by the country where the power supply is used.
What should you not do to a power supply?
Open it up. The capacitors inside can hold charge for a long period of time. They could harm you.
What does the switch set the power inputs as?
110V/115V or 220V/230V.
