Electricity

Question 1

What do Volts measure?

Answer 1

EMF
Potential Difference

Question 2

What unit is the strength of an electric current measured in?

Answer 2

Amphere
Amps

Question 3

Another term for power?

Answer 3

Wattage
Watts

Question 4

Where should Romex NMD be used?

Answer 4

Dry enviroments, with no chance of physical damage.

Question 5

What must be used with Armoured Cable?

Answer 5

Anti-shorts

Question 6

WHat does EMF stand for in electrical

Answer 6

Electromotive force
Is used to indicate electrical pressure or voltage.

“Potential difference”

Question 7

What does A.C stand for?

Answer 7

Alternating Current

A.C is not constant, it’s going from negative to positive in a sine wave

Question 8

What does R.M.S stand for?

Found on a multimeter.

Answer 8

Root Means Square

Modern multimeters calculate the actual Voltage using a formula.

Question 9

What does Current define in a electrical system?

Answer 9

Is a measurement of the rate of flow or electrons.

Question 10

What is a ampere in an electrical system?

Answer 10

An ampere is one coulomb of electrons flowing past a given point in one second.

One coulomb is aprox.
6,280,000,000,000,000,000 or 6.28x10e18 electrons

Question 11

What is resistance in an electrical circuit?

Answer 11

Basically “Oppostion to the flow of electrons”

All material have some resistance to the flow of electrons.

Question 12

What four things effect resistance in an electrical circuit?

Answer 12

1 Material(Aluminum vs Copper)
Diameter( 8awg vs 6awg)
Length (25’ vs 50’)
Temperature (60Celsuis vs 75 celsuis)

Question 13

You connect an ammeter in ____ with the load?

Series/Parallel

Answer 13

Series

Question 14

You connect a Voltmeter in____ across the load

Series/Parallel

Answer 14

Parallel

Question 15

In a series circuit, how does resistance act?

Answer 15

Total resistance is added together.
(r1+r2+r3=RT)

Question 16

In a series circuit, how does Amperage behave across each load?

Answer 16

The amperage is constant througout a series circuit.
i1=i2=iT

i = Amperage

Question 17

In a series circuit, how does Voltage behave across each load?

Answer 17

The total voltage is equal to all the voltage drops across each load.
ET=E1+E2+E3

E=Voltage

Question 18

In a parallel circuit, how does Resistance act?

Answer 18

Total resistance is less then the lowest sum in the circuit.
{1/(1/R1+1/R2+1/R3)=Rt}**

**Formula for finding resistance in parallel circuit

Question 19

How does Voltage behave in a parallel circuit?

Answer 19

Voltage is constant across each load.
(Et=E1=E2)

Et= voltage total/Total Voltage

Question 20

In relation to a parallel circuit, how will amperage act?

Answer 20

The Current total is all individual loads added together.
(I1+I2=It)

Question 21

In a series circuit, if one component fails, what happens to the rest of the circuit?

Answer 21

The entire circuit stops working

Question 22

If you add more resistors to a series circuit, the total resistance will:

Answer 22

Increase

Question 23

In a series circuit, if the total voltage is 12V and there are three equal resistors, what is the voltage drop across each resistor?

Answer 23

4V

Question 24

When calculating the total resistance in a series circuit, you should

Answer 24

Add them together

Question 25

In a series circuit, the sum of the individual voltage drops across each resistor is?

Answer 25

Equal to the total voltage

Question 26

If the current through a series circuit is 2A, and the resistance is increased, the current will

Answer 26

Decrease

Question 27

In a series circuit with different resistors, the resistor with the highest resistance will have the_ _ _ _ _ Voltage Drop

Answer 27

Highest

Question 28

In a parallel circuit, if one branch is opened or disconnected, what happens to the other branches?

Answer 28

They will continue to work

Question 29

The electrical service supplied to a building is measured in?

Answer 29

Watts | Watts=Power, Power=Watts

Question 30

Homes which are heated by electricity require what size of service? | Amps

Answer 30

200Amps

Question 31

Which gauge of wire is normally used for residential lighting and receptacles?

Answer 31

14/2 AWG

Question 32

The GFCI will trip when it senses what change of current flow?

Answer 32

0.005 Amps

Question 33

What size of grounding/bonding wire is used?

Answer 33

6 AWG

Question 34

The voltage sine wave of a three-phase wire system is out of phase with each other by_ _ _ _ Degrees

Answer 34

120 | 360 Deg. divided in 3 = 120 degrees

Question 35

Failure of a conductor's insulation, causing the conductor to touch casing and create line-to-ground, is called a?

Answer 35

Short Circuit | You SHORT the CIRCUIT by going back to the source.

Question 36

A current surge when a motor starts up is called

Answer 36

An Overcurrent | Motor pulling to many amp very quickly

Question 37

The use of worn out or seized bearings in electrical equipment could cause

Answer 37

Overload | Pulling to many amps for far to long.

Question 38

What color is a fuse rated for up to 15 Amps?

Answer 38

Blue

Question 39

What color is a fuse rated for up to 20 Amps?

Answer 39

Red

Question 40

What color is a fuse rated for up to 30 Amps?

Answer 40

Green

Question 41

What is the maximum voltage considered to be a low voltage system? | When compared to power lines!

Answer 41

750V

Question 42

The ability of a material to be drawn into wire form is called:

Answer 42

Ductility

Question 43

When taking a voltage reading, how should the meter be connected?

Answer 43

In parallel with the load being checked.

Question 44

A **basic** multimeter incorporates which electrical meters?

Answer 44

Voltmeter, Ammeter, Ohmmeter

Question 45

What is the power rating of a secondary stage in a transformer if it has 24 volts and 10 amps?

Answer 45

240W P=V*A

Question 46

How many wires are contained in a service conductor to a residential panel? | From the road to the main breaker panel

Answer 46

2 Hot, 1 Neutral, 1 Ground

Question 47

How are transformers rated?

Answer 47

Volt-Amps (VA)

Question 48

The electrical code requires all electrical connections be | Where do you make a wire connection

Answer 48

Made in a junction or outlet box

Question 49

Switches are located in which leg of the circuit?

Answer 49

Hot, You want to interupt power going into the equipment. | Dangerous to do on the Neutral!!!!

Question 50

Thermocouples generate DC voltage in which range?

Answer 50

0-30mV

Question 51

When the pilot fails, the thermocouple must cool down and de-energize the safety shut-off valve or safety switch within:

Answer 51

180 seconds

Question 52

Thermocouples are only approved for gas appliances with inputs up to and including: | How many Btu/H

Answer 52

400,000 Btu/H

Question 53

A thermocouple only generates a voltage if the temperature difference between the hot and cold junctions is at least?

Answer 53

400°F

Question 54

The pilot flame should only heat the first | How much should the flame cover in inches.

Answer 54

1/2"

Question 55

Thermopiles generate a DC voltage of?

Answer 55

250mV-750mV

Question 56

What is one non-desirable characteristic of a normal pilot flame?

Answer 56

A Small, Hard, Sharp flame

Question 57

The thermocouple should be replaced when a open test reading of what occurs?

Answer 57

0-15mV

Question 58

What does A.W.G stand for

Answer 58

American Wire gauge

Question 59

How many volts does a thermostat send to an A/c to power the contactor

Answer 59

24V

Question 60

What unit of measurement are breakers designated?

Answer 60

Amps

Question 61

What does a breaker connect to in a breaker panel box?

Answer 61

Hot Bus Bar

Question 62

What determines the wire gauge and breaker size?

Answer 62

Current

Question 63

Which color wire nut would be used for two 14AWG conductors?

Answer 63

Orange

Question 64

Which color wire nut would be used for two 10AWG conductors?

Answer 64

Yellow

Question 65

Which color wire nut would be used for three 14AWG conductors?

Answer 65

Yellow

Question 66

Which color wire nut would be used for two 18AWG conductors?

Answer 66

Blue

Question 67

Which color wire nut would be used for three 18AWG conductors?

Answer 67

Orange

Question 68

How should conductors be terminated into a screw terminal?

Answer 68

The Approved Method

Question 69

How far out of the box shall wires extend?

Answer 69

Minimum of 6"

Question 70

When can junction boxes be uncovered?

Answer 70

NEVER

Question 71

What is the minimum distance for a Natural gas regulator must be from a source of ignition? Propane Regulator?

Answer 71

Natural Gas is 3' Propane is 10'