Basic Electricity Flashcards
If a DC power supply of 20 volts causes 2 amps of current to flow in a circuit
The resistance of the circuit is 10 ohms
A _________ is often used as a graphic representation of alternating current
Sine wave
Which of the following is true regarding current flow in a parallel circuit?
The paths with lower resistance will have higher current flow
A control transformer rated at 50 VA and a 25 volt secondary voltage should be protected with a
2 amp fuse
The symbol used for electrical pressure is
“E”
What happens to the current if the voltage in a circuit doubles and nothing else changes?
The current will decrease by ½
1 millivolt equals
1/1000 of a volt
Which meter is used to test for potential?
Voltmeter
To read the amperage draw from an alternating electrical device
Set the meter to read amperage and clamp the meter around one of the conductors feeding power to the device
When testing a compressor motor with an ohmmeter, what reading would be obtained if its internal over-load is in the open position?
Run to common—infinite ohms
The capacitor analyzer is used to measure
Shorted or open capacitors and micro-farad values
When should a mega-ohmmeter never be used?
When the system is in a vacuum
The four components of a circuit are
Power source, current path, load and switch
Upon start-up of a roof top air conditioning system it is found that the condenser fan motors are rotating in the wrong direction. What should be done to correct the problem?
Disconnect the power and change any two phase leads of the incoming power
A single phase 120/240 volt electric service is made up of
L1, L2 and Neutral
