UNIT 31 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX
31-1) Describe the basic structure of the atom.
Atoms are made of small particles called protons, neutrons, and electrons.
31-2) Define free electron.
31-3) What is the difference between a generator and an alternator?
31-4) What is the difference between static electricity and dynamic electricity?
31-5) What precautions should be taken before handling printed circuit boards?
31-6) Give an example of the use of static electricity in the HVACR field.
31-7) Give the units used to measure the following electrical circuit characteristics
Potential volts
31-8) Explain the relationship between current and resistance in an electrical circuit.
31-9) Explain why copper is a good electrical conductor.
31-10) Explain the difference between direct current and alternating current.
31-11) What is meant by the frequency of AC current?
31-12) What is Ohm’s law?
31-13) What is the current draw of a circuit with a resistance of 6 ohms when 120
volts is applied to the circuit?
31-14) What is the resistance of a circuit operating with a current draw of 5 amps and
30 volts?
31-15) What voltage is being supplied to circuit with a resistance of 25 ohms and a
current draw of 5 amps?
31-17) What is the current draw of a 1,500 W electric heater operating on a 120 V
power supply?
31-18) What three elements are required for all electric circuits?
31-19) Name and describe the three types of path arrangements for circuits.
The series circuit, which allows only one path for the current to flow;
31-20) What is the difference between a short circuit and on open circuit?
31-21) Explain how a switch controls whether a load operates or does not operate.
31-22) Why are parallel circuits used as to supply power for loads in
HVACR equipment?
31-23) Find the total resistance of the complete circuit with 240 volts and R1 = 6
ohms and R2 = 4 ohms.
31-24) Draw a series circuit with 3 loads
31-25) Draw a parallel circuit with 4 loads.
31-26) Draw a series parallel circuit with one switch and two loads. The loads should
be in parallel with each other, but is series with the switch.
31-27) Explain how to calculate the resistance of a series parallel circuit.
First, identify the major parallel and series sections of the circuit.