Unit 12

Question 1

Continually and rapidly reversing current 

Answer 1

Alternating current

Question 2

Protects the circuit from an overload

Answer 2

Circuit breaker

Question 3

Device used to measure resistance

Answer 3

Ohmmeter

Question 4

Component that is neither a conductor or insulator, but a partial conductor

Answer 4

Semiconductors

Question 5

Coil of wire wrapped around an iron core that induces a current to another coil of wire, wrapped around the same iron core

Answer 5

Transformer

Question 6

Unit of power

Answer 6

Watts

Question 7

Smallest amount of a substance that can exist

Answer 7

Atom

Question 8

Used to measure current without breaking a circuit to install the meter

Answer 8

Clamp on meter

Question 9

Amount of charge that can be stored

Answer 9

Capacitance

Question 10

When an atom has more electrons than protons

Answer 10

Negative charge

Question 11

Total voltage is applied across each resistance. Current is divided between the different loads, and total current is equal to the sum of the current in each branch. Total resistance is less than the value of the smallest resistance.

Answer 11

Parallel circuit

Question 12

Used to measure current in a circuit

Answer 12

Ammeter

Question 13

Materials with a few electrons in the outer orbit, such as gold, silver, copper and aluminum

Answer 13

Conductor

Question 14

Has a negative charge and travels around the nucleus in orbits or shells

Answer 14

Electron

Question 15

Total effect of resistance in a circuit consist of pure resistance, inductive, reactants, and capacitive reactants

Answer 15

Impedance

Question 16

A resistor that is sensitive to temperature

Answer 16

Thermistor

Question 17

A force causing a magnetic field to attract ferrous materials, or where light poles of a magnet repel, and unlike poles, attract each other

Answer 17

Magnetism

Question 18

May be used as a switch or a device to amplify an electrical signal

Answer 18

Transistor

Question 19

Voltage is divided across the different resistances. Total current flows through each resistance or load. Resistances are added together to obtain total resistance.

Answer 19

Series circuit

Question 20

Device that allows heat to be dissipated into the surrounding air

Answer 20

Heat sink

Question 21

T/F
In a capacitive circuit, volt lags current

Answer 21

True

Question 22

T/F
Total resistance of a parallel circuit is less than the value of the smallest resistance

Answer 22

True

Question 23

T/F
Current in a series circuit is the same, regardless of where it is measured

Answer 23

True

Question 24

T/F
In a pure resistive circuit, voltage lead current

Answer 24

False

Question 25

T/F If wire is wound into a coil, and a circuit is passed through it, the coil, carrying an electrical circuit is called a solenoid/electromagnet

Answer 25

True

Question 26

T/F Electrons flow from positive to negative in a direct current circuit (DC)

Answer 26

False

Question 27

T/F Inductive loads, primarily generate a magnetic field, whereas resistive load generate light and or heat

Answer 27

True

Question 28

T/F Lightbulbs in a serious circuit will all have the same bright, regardless of the resistance, and each lightbulb

Answer 28

False

Question 29

T/F As resistance in a circuit increases, current decreases

Answer 29

True

Question 30

T/F A rectifier is used to change AC current into DC current

Answer 30

True

Question 31

The full load amperage (FLA) reading on a fan motor data plate is 1.5A. What is the lock rotor amperage (LRA) for the fan motor? 

Answer 31

7.5A. Divide LRA by 5 to get FLA

Question 32

The proper way to discharge a capacitor before testing it is to use a resistor that has a resistance of _______ Kohms and rated for __________watts

Answer 32

20K ohms ; 5watts

Question 33

How are the three terminals on a dual capacitor marked?

Answer 33

Common, herm, fan

Question 34

As temperature in a wire increases, resistance _____________.

Answer 34

Increases

Question 35

What would the voltage in a DC circuit be if there were a current flow of .5 A and a load resistance of 50 ohms?

Answer 35

25 volts.

Question 36

Draw the electrical symbol for a temperature switch that closes on the rise, commonly used and a cooling thermostat

Question 37

Draw the electrical symbol for a pressure switch in a normally closed position (N.C)

Question 38

Draw the electrical symbol for an air core transformer