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Flashcards in HVAC electrical test Deck (85)
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1

What is current flow?

The flow of electrons in the circuit.

2

What is impedance?

Opposition to alternating current flow?

3

Like charges will..

Repel each other.

4

Any material that will readily release electrons is called?

A conductor

5

The symbol for current is?

I

6

Electricity can produce

Heat, light, magnetism

7

The safety ground conductor is usually color coded?

Green

8

An electron has?

A negative charge

9

What is resistance?

Opposition to current flow

10

How many watts of power are used by a heater operating at 460 volts and drawing 5 amps?

2300

11

What type of meter uses it's own battery?

Ohmmeter

12

In electrical wiring, a black colored wire usually indicates....

The hot conductor

13

How are fuses sized?

Amps and volts

14

Two 120 volt motors are wired in a series, one is a 60 watt motor, the other is a 4 watt motor. The result would be...?

Neither motor would operate normally

15

What would be the result of three defrost heaters, each 12.5 ohms, wired in a series to a 115 volt power supply, it the heaters were to supply a 360 watt heating load?

Heaters do not energize

16

What is generally considered to be the maximum allowable (+ or -) supply voltage variation?

5%

17

Capacitors are rated in...

Microfarads and volts

18

When testing a capacitor with an analog ohmmeter, the needle on the meter should..

Deflect towards zero then return to infinite reading.

19

What is the term used to describe the output side of a transformer?

Secondary side

20

One horsepower is equal to _______ watts.

746

21

How much resistance must be placed in a 110 volt circuit in order to limit the current to 2 amps?

A. 55 ohms
B. 110 ohms
C. 30 ohms
D. None of the above

55 ohms

22

A parallel circuit contains a 18 ohm and a 9 ohm resistor. The total resistance equals...

A. 6 ohms
B. 27 ohms
C. 8 ohms
D. 10 ohms

6 ohms

23

In a series circuit, the voltage drop across each resistance (load) will...

A. Always add up to equal the source voltage.
B. Depend on the value of each resistor.
C. Depend on the current flow in the circuit.
D. All of the above

All the above

24

The total resistance of a parallel circuit will be...

A. The sum of all resistances
B. Equal to the largest resistance
C. Equal to the smallest resistance
D. Less than the smallest resistance.

Less than the smallest resistance

25

Which of the following statements about current is true?

A. Current flow is the same as voltage
B. Current flow will increase when voltage increases.
C. Current flow will increase when resistance increases.
D. Current flow will decrease when voltage increases.

Current flow will increase when voltage increases.

26

When resistors are wired in parallel...
A. The current through any one resistor will be the same as the total circuit current.
B. The voltage drop across each resistor will be the same as the applied source voltage.
C. The voltage drop across each resistor will depend on the value of each resistor.
D. The total resistance is determined by adding the values of each resistor.

The voltage drop across each resistor will be the same as the applied source voltage.

27

Which of the following is equal to 2.1 KV?
A. 21 volts
B. 210 volts
C. 2100 volts
D. 21000 volts

2100

28

Which of the following is equal to 100 milliamps?
A. 1.0 amperes
B. 10.0 amperes
C. 0.10 amperes
D. 0.01 amperes

0.10

(each amp is equal to 1000 milliamps)

29

A capacitor analyzer is designed to..
A. Read power factor percentage
B. Diagnose an open or shorted capacitor.
C. Read the microfarad rating of a capacitor.
D. All of the above

Read the microfarad rating of a capacitor

30

A 240 volt, 3 wire circuit can be split into two 120 volt circuits.
True or false?

False