Line E Flashcards
What are the tiny particles that matter is made of called?
a. Compounds
b. Atoms
c. Ions
d. Protons and neutrons
Atoms
What are elements called that have atoms with electrons that are easily freed?
a. Ions
b. Conductors
c. Insulators
d. Elements
Conductors
Which of the following best describes copper?
a. Conductor
b. Insulator
c. Semiconductor
d. Valence electron
Conductor
Why are insulators useful?
a. They transport an electrical charge.
b. They do not transport an electrical charge.
c. They readily release valence electrons.
d. They will ionize easily when subjected to voltage.
They do not transport an electrical charge.
In what units is current measured?
a. Volts
b. Amperes
c. Ohms
d. EMF
Ampres
A source of electromotive force can be from a chemical reaction.
True
In a DC circuit the poles alternate from positive to negative.
False
What is the device called that is used to turn a circuit on and off?
a. A control
b. A conductor
c. A load
d. A protector
A control
Which of the following best describes an electric motor?
a. A control
b. A load
c. A fuse
d. A conductor
A load
If resistance in a circuit is 6 Ω and the pressure is 24 V, what is the current flow?
a. 2 A
b. 4 A
c. 6 A
d. 8 A
4 A
If a circuit had a current flow of 8 A and the resistance is 20 Ω, what is the pressure in volts?
a. 120 V
b. 160 V
c. 2.5 V
d. 25 V
160V
If a circuit has a current flow of 5 A and a pressure of 120 V, what is the resistance?
a. 24 Ω
b. 12 Ω
c. 6 Ω
d. 3 Ω
24 Ω
How much power will a heater produce if it uses 15 A in a 120 V electrical system?
a. 1800 W
b. 1500 W
c. 900 W
d. 1200 W
1800 W
How many amps will flow through a 60 W headlight bulb in a 24 V system?
a. 6 A
b. 2.5 A
c. 25 A
d. 8 A
2.5 A
Use Ohm’s law to complete the following chart.
Use the power formula to complete the following chart.
What takes the place of a ground return wire in a single wire system?
a. Fuse
b. Case ground
c. Circuit breaker
d. Chassis
Chassis
How many paths does a series circuit have for current flow?
a. 1
b. 2
c. 3
d. 4
1
What is a circuit called that has more than one path for current flow?
a. Series circuit
b. Complex circuit
c. Compound circuit
d. Parallel circuit
Parallel circuit
What must the total voltage drop in a circuit be equal to?
a. The source voltage
b. The first voltage drop
c. Half the source voltage
d. Twice the source voltage
The source voltage
A 12 V circuit with a 4 ohm resistor will have a current of 6 A.
False
A 120 V circuit with a current of 10 A will have a load with what resistance?
a. 12 Ω
b. 24 Ω
c. 6 Ω
d. 10 Ω
12 Ω
If one load fails in a parallel circuit, all other loads will fail.
False
What is the total resistance in a series circuit with four resistors rated at 2 Ω each?
a. 2 Ω
b. 4 Ω
c. 6 Ω
d. 8 Ω
8 Ω
A 120 V parallel circuit has three resistors: 20 Ω, 12 Ω, and 24 Ω. What is the current?
a. 6 A
b. 18 A
c. 21 A
d. 24 A
21 A
What is the total resistance for a 120 V circuit with three resistors of 20 Ω, 12Ω, and 24 Ω in parallel?
a. 6 Ω
b. 8 Ω
c. 12 Ω
d. 24 Ω
6 Ω
There are three types of magnets: natural, artificial, and electric.
True
Natural magnets have the strongest force.
False
If the south poles of two magnets are brought together, what they will do?
a. Conduct
b. Relate
c. Saturate
d. Repel
Repel
Changing which of the following will also change the strength of an electromagnet?
a. Direction of current flow
b. Size of wires
c. The length of the core
d. Amount of current flow
Amount of current flow
What is the core of an electromagnet usually made from?
a. Air
b. Soft iron
c. Aluminum
d. Copper
Soft iron
What two elements must be combined with a conductor to generate a voltage?
a. Magnetic field and a current
b. Current and movement
c. Coil and a magnet
d. Magnetic field and movement
Magnetic field and movement
Magnetic lines of force never cross.
True
Match the device on the left with its purpose on the right.
a. Circuit breaker 1. Protects circuits
b. Relay 2. Electric switch
c. Solenoid 3. Variable control
d. Rheostat 4. Movable core
a. Circuit breaker (1. Protects circuits)
b. Rheostat (3. Variable control)
c. Relay (2. Electric switch)
d. Solenoid (4. Movable core)
What best describes tapped or stepped resistors?
a. They have two or more fixed values.
b. They have only one unchangeable rating.
c. They have a variable range of resistance.
d. They are used to control charging systems.
They have two or more fixed values.
How is a fuse different from a circuit breaker?
a. A fuse acts like a diode.
b. A circuit breaker doesn’t need a ground.
c. A fuse can be reset and a circuit breaker cannot.
d. A circuit breaker can be reset and a fuse cannot.
A circuit breaker can be reset and a fuse cannot.
6 gauge wire is smaller than 18 gauge.
False
What are conductors normally made from?
a. Steel
b. Copper
c. Soft iron
d. Aluminum
Copper
Receptacles are one-half of a two-piece multi-contact connector.
True
What are circuit breakers, fuses, and thermal limiters all examples of?
a. Relays
b. Switches
c. Receptacles
d. Protection devices
Protection devices
How many gauges of difference must there be between a fusible link and a conductor?
a. 2
b. 4
c. 6
d. 8
4
Relays require a power circuit and a control circuit.
True
What are transformers used for?
a. To act like a relay
b. To increase amperage
c. To increase or decrease voltage
d. To change the current from DC to AC
To increase or decrease voltage
Who is responsible for testing all electrical components?
a. ITA
b. NSA
c. CSA
d. DNA
CSA
Closed means the circuit is complete and conducting.
True
What voltage other than 120 V does a residential system use?
a. 180 V
b. 200 V
c. 240 V
d. 280 V
240V
A schematic diagram is often called a ladder diagram.
True
What is the fourth type of wiring diagram, in addition to schematic, wiring, and block
diagrams?
a. Line
b. Oblique
c. Pictorial
d. Isometric
Pictorial
A schematic diagram shows all physical locations of components.
False
For which operations is a wiring diagram best suited?
a. Diagnosing
b. Sequencing
c. Installation
d. Troubleshooting
Installation
A pictorial diagram is used to locate components in complex systems.
True
A block diagram includes symbols.
False
Typical house wiring is an example of a series circuit.
False
If one load fails in a series circuit, what happens to the other loads?
a. They will all fail.
b. A fuse will blow.
c. Nothing happens.
d. The rest remain working.
They will all fail.
As more resistors are added in series, what increases?
a. Power
b. Voltage
c. Current
d. Resistance
Resistance
A series circuit allows the control of current flow.
True
Which of the following is true about a parallel circuit?
a. Voltage will be different at each load.
b. Voltage will be the same at each load.
c. Current will be the same at each load.
d. Resistance will be the same at each load.
Voltage will be the same at each load.
The three-wire circuit is an example of which of the following?
a. Hot jumping
b. Series aiding
c. Parallel aiding
d. Backpacking circuit
Series aiding
For what purpose is a circuit grounded?
a. Safety
b. Series aiding
c. Circuit protection
d. Easier installation
Safety
What is the result of connecting three 6 V batteries in series?
a. 12 volts are produced.
b. 18 volts are produced.
c. 24 volts are produced.
d. The voltage doesn’t change.
18 volts are produced.
Which of the following must apply to power sources connected in parallel?
a. Unlike terminals must be connected.
b. They must be connected with a fuse.
c. Like terminals must be connected.
d. They must have a transformer between them.
Like terminals must be connected.
For voltages to accumulate in series aiding, what must occur?
a. Correct polarity
b. Circuit protection
c. Similar amperages
d. Dissimilar amperage
Correct polarity
If two 12 V batteries are connected in parallel, what will the voltage be across any load?
a. 6 V
b. 12 V
c. 24 V
d. 48 V
12 V
Which term best describes a material that allows electrical energy to pass through it?
a. Resister
b. Insulator
c. Conductor
d. Connector
Conductor
Which of the following best describes the term electrical cable?
a. Any wire
b. Any insulated wire
c. Multiple wires grouped together in a common insulation
d. Multiple insulated wires grouped together in a common sheathing
Multiple insulated wires grouped together in a common sheathing
What is the primary purpose of insulation on wires?
a. To protect the wire
b. To make installation easier
c. To prevent unwanted current flow
d. So the wire can be colour coded
To prevent unwanted current flow
When is stranded wire used?
a. On short wires
b. When cost is a factor
c. On straight runs of wire
d. When flexibility is needed
When flexibility is needed
Wire is sized by gauge: the higher the number, the larger the wire.
False
What should be done to stranded wire prior to bending?
a. It should be curled.
b. It should be tinned.
c. It should be wound.
d. It should be twisted.
It should be tinned.
Solderless connections are more costly than soldering.
False
What is one advantage to a twist-on connector?
a. It is permanent.
b. One size fits all.
c. It will not come apart.
d. It can be removed easily.
It can be removed easily
It doesn’t matter what material the conductor is made from when making a connection.
False
What type of connector should be used to create a permanent splice?
a. Twist
b. Winged
c. Crimp-on
d. Set screw
Crimp-on
Safety factors such as toxic fumes and splashing flux should always be addressed when soldering.
True
Which of the following best describes the process of surface penetration?
a. Bonding
b. Wetting
c. Soldering
d. Prepping
Wetting
Which of the following should apply when tinning stranded wire?
a. The strands should be thickly coated.
b. The strands should be visible under the solder.
c. The solder should wick up underneath the insulation.
d. A large blob of solder should form at the end of the wire.
The strands should be visible under the solder.
Metals like aluminum and iron wet easily.
False
What is the purpose of flux?
a. To remove oxides
b. To clean the metal
c. To assist with heating
d. To remove the solder
To remove oxides
What is the most common alloy used for solder?
a. Tin-lead
b. Lead-silver
c. Tin-copper
d. Lead-copper
Tin-lead
Soldering pencils are used for heavy-duty applications.
False
What must be done to a soldering tip prior to soldering?
a. Tin it.
b. Wash it.
c. Wire brush it.
d. Heat it red hot.
Tin it.
What should be done to an overly corroded soldering tip?
a. Nothing.
b. Re-tin it.
c. Throw it away.
d. Dress it with a fine file.
Dress it with a fine file.
What is the purpose of a heatsink?
a. To protect the solder
b. To pull flux to the joint
c. To pull heat to the area for soldering
d. To pull heat away from certain components
To pull heat away from certain components
What would cause a solder joint to be piled up and lumpy in appearance?
a. Insufficient heat
b. Lack of flux
c. Poor tinning
d. A corroded tip
Insufficient heat
What are multimeters used to test, in addition to amperage and voltage?
a. Pressure
b. Humidity
c. Resistance
d. Temperature
Resistance
Analog meters are more popular than digital.
False
How many volts are in 2200 mV?
a. 0.22 V
b. 2.2 V
c. 22 V
d. 220 V
2.2 V
It is important to turn the circuit off before checking voltage.
False
What would happen if you connected the probes backwards when checking voltage?
a. Damage to the DDM would occur.
b. Damage to the circuit would occur.
c. A negative voltage would be read.
d. It doesn’t matter which way they go.
A negative voltage would be read.
What is one important safety technique when testing electrical circuits?
a. Wearing gloves
b. Wearing safety glasses
c. Using the one-hand technique
d. Using the two-hand technique
Using the one-hand technique
The first step when using an autorange DDM is to select the range required.
False
A circuit must be broken to test current.
False
Is an amperage test done in series or parallel?
a. Series
b. Parallel
Series
When is it important to turn off a DDM to extend battery life?
a. After checking voltage
b. After checking amperage
c. After checking resistance
d. Never; it turns off automatically
After checking resistance
When the probes are touched together in a resistance test, what should the meter read?
a. 0
b. Infinity
c. OL
d. Nothing
0
How many ohms are in 2.125 kΩ?
a. 21.25 Ω
b. 212.5 Ω
c. 2125 Ω
d. 21 250 Ω
2125 Ω
What is the name of the test used when testing a circuit for an open?
a. Infinity test
b. Overload test
c. Continuity test
d. This test cannot be done.
Continuity test
What is the lowest amperage at which fatal injury can occur in a human?
a. 15 A
b. 0.15 A
c. 50 mA
d. 15 mA
50 mA
If you measure voltage across a switch, what state is it in?
a. Open
b. Closed
Open
If you measure correct voltage across a load but the load doesn’t work, what is wrong?
a. There is no power.
b. There is no current.
c. A switch is open.
d. The load has failed.
The load has failed.
Refer to Figure 1. If you have a reading at point 4, but not at 5, what is the problem?
a. The load has failed.
b. The switch is open.
c. The wiring has failed.
d. The ground has failed.
The wiring has failed.
Refer to Figure 1. If you have a reading at 5 and zero at 6, what is the problem?
a. The load has failed.
b. The switch is open.
c. The wiring has failed.
d. The ground has failed.
The load has failed.
What is always the first step when testing for resistance?
a. Check the load.
b. Remove the component.
c. Turn the circuit power on.
d. Turn the circuit power off.
Turn the circuit power off.
What is the best test for checking if a heating element is faulty?
a. Voltage test
b. Continuity test
c. Amperage test
d. They cannot be tested.
Continuity test
What will increase when power sources are connected in series?
a. Voltage
b. Current
c. Resistance
d. Continuity
Voltage
