Basic Electricity

The unit and symbol for voltage is:

Amp and I

Volt and E

Watt and W

Ohm and R

Correct! Wrong!

The unit and symbol for current is:

Amp and I

Volt and E

Watt and W

Ohm and R

Correct! Wrong!

The unit and symbol for resistance is:

Amp and A

Volt and E

Watt and W

Ohm and R

Correct! Wrong!

The unit and symbol for power is:

Amp and A

Volt and E

Watt and W

Ohm and R

Correct! Wrong!

The concept of electron flow on a conductor can best be described as:

wattage

current

resistance

voltage

Correct! Wrong!

Resistance can best be described as:

speed of flow of electrons

electrical pressure

flow of electrons through a circuit

opposition to flow of electrons (current)

Correct! Wrong!

Voltage can best be described as:

electrical pressure

resistance

flow of electrons through a circuit

speed of flow of electrons

Correct! Wrong!

Choose a good conductor from the list below:

copper

wax

glass

wood

Correct! Wrong!

Choose a good semi-conductor from the list below:

porcelain

silicon

wax

plastic

Correct! Wrong!

Choose a good insulator from the list below.

iron

rubber

silver

aluminum

Correct! Wrong!

The magnetic force which exists between any two objects that are similarly charged is:

weak

strong

one of repulsion

one of attraction

Correct! Wrong!

The magnetic force which exists between any two objects that are oppositely charged is:

weak

strong

one of repulsion

one of attraction

Correct! Wrong!

A lead-acid storage battery is an example of which method of producing electricity?

chemical

friction

light

pressure

Correct! Wrong!

An alternator or a generator would be good examples of which method of producing electricity?

induced

friction

chemical

pressure

Correct! Wrong!

A good example of mutual induction in an automobile electrical system is:

coil

battery

headlight switch

starter motor

Correct! Wrong!

The state of the tail light switch shown is such that one of the following terms could be applied to this circuit:

closed circuit

short circuit

series circuit

open circuit

Correct! Wrong!

Which of the following is closer to the description of a series circuit?

devices connected with a break at a control device

devices connected to form only one current path

devices connected to form more than one path for current flow

devices connected to have a common voltage

Correct! Wrong!

Calculate the total resistance of three resistors which are 60 ohms, 60 ohms and 15 ohms connected in parallel.

45 ohms

10 ohms

135 ohms

105 ohms

Correct! Wrong!

Calculate the current flowing in a circuit if the load is three resistors of 150 ohms, 450 ohms, and 120 ohms, connected in series to a 24 volt supply:

887A

0.0333A

0.413A

0.333A

Correct! Wrong!

If the supply voltage is 12 volts, the current flow is 8 amps, what is the resistance?

.66 ohms

1.5 ohms

96 ohms

none of the above

Correct! Wrong!

Load devices are normally connected in parallel so that:

they call all be rated the same current rating

they can all be given the same fuse rating

they need not be fused

they can all be operated at independent current ratings

Correct! Wrong!

Which of the following correctly represents the magnetic laws of attraction and repulsion?

like poles repel, unlike poles repel

like poles repel, unlike poles attract

like poles attract, unlike poles repel

none of the above

Correct! Wrong!

Relays and solenoids all depend upon the principle of:

electrostatics

permanent magnetism

interaction

electromagnetism

Correct! Wrong!

The magnetic field (EMF) that is found near a current-carrying conductor moves:

only at the battery terminals

through the conductor

along conductor

around the conductor in a circular way

Correct! Wrong!

The rule that determines the direction of the magnetic field of a current-carrying conductor is:

the rule of thumb

the three finger left hand rule

the three finger right hand rule

the right hand rule

Correct! Wrong!

How can a current-carrying wire be used to form a practical electromagnetic?

twist the wire together

leave the wire as it is

wind a number of loops in alternate directions

wind a number of loops in the same direction

Correct! Wrong!

What advantages do electromagnets have over permanent magnets?

electromagnets are easily constructed

electromagnets do not use as much power as permanent magnets

electromagnets are easily controlled

none of the above

Correct! Wrong!

What determines the polarity of an electromagnet?

the polarity of the power source

the amount of current

the gauge of wire used

the core material

Correct! Wrong!

Two coils are wound in the same direction, each with the same number of turns and are connected to the same source. One coil has an air core and the other an iron core. The iron core causes:

no change in the magnetic field

an increase in the density of the magnetic field

a decrease in the density of the magnetic field

magnetic saturation to occur

Correct! Wrong!

To identify an electrical meter which is to be used to measure resistance, the meter face will be marked:

ammeter

wattmeter

ohmmeter

voltmeter

Correct! Wrong!

A milli volt is:

1/1,000v

1/1,000,000v

1,000v

1,000,000v

Correct! Wrong!

Basic ammeters are connected in _________________ with the circuit:

series

parallel

series parallel

a shunt

Correct! Wrong!

To correctly measure the potential difference across a resistor in a circuit, a voltmeter is connected:

in parallel with the resistor - supply off

in parallel with the resistor - supply on

in series with the resistor - supply on

in series with resistor - supply off

Correct! Wrong!

If an analog ohmmeter is manually set before use to read below zero, them in use the meter will read:

low initially, then correct across the rest of the scale

low all across the scale

the machine will self-correct all across the scale

correctly because static electricity may have caused the needle to move

Correct! Wrong!

Calculate the value of the resistance in an engine''s block heater circuit if the ammeter reads 7.5 amperes and the voltmeter reads 120 volts.

16.0 ohms

0.0625 ohms

900 ohms

127.5 ohms

Correct! Wrong!

Electrical current is describe as the flow of tiny particles called:

electrons

iron

elements

microns

Correct! Wrong!

1. Magnets can cause electrons to flow in a conductor. 2. Electron flow in a conductor can produce magnetism. Of these two statements:

both are false

both are true

the first is true; the second is false

the first is false; the second is true

Correct! Wrong!

If excessive current flows through a fuse, the metal strip melts and:

opens the circuit

closes the circuit

grounds the circuit

shorts the circuit

Correct! Wrong!

Equipment marker lights are wired in series.

True

False

Correct! Wrong!

A dim light on a vehicle may be caused by a poor ground.

True

False

Correct! Wrong!

Voltage drop in a circuit may be caused by:

6 volt batteries

incorrect fuse rating

poor connections.

soldered and sealed connections

Correct! Wrong!

When disconnecting a battery from a charger you should always:

disconnect both terminals at the same time

disconnect negative terminal first

shut off the charger first

check specific gravity first

Correct! Wrong!

Series circuits have ____________ path for current flow.

one

more than one

a grounded

a shorted

Correct! Wrong!

Each resistor in a series circuit will cause a ____________ drop across itself:

wattage

voltage

amperage

resistance

Correct! Wrong!

The voltage drop across resistors in a basic parallel circuit will ____________ the battery voltage.

be equal to

be one-half

reduce

step up

Correct! Wrong!

The force needed to cause current to flow in a circuit is called:

gravity

voltage

amperage

conductance

Correct! Wrong!

An electromagnet''s strength may be increased by:

increasing the current through the coil

adding more loops to the coil

adding an iron core inside the coil

all of the above

Correct! Wrong!

If resistance is doubled and the voltage remains the same:

current will remain the same

electromotive force will be cut in half

current flow will double

current flow will be cut in half

Correct! Wrong!

A short can be considered to be "copper to copper" in a circuit.

True

False

Correct! Wrong!

While testing a solenoid coil, an ohmmeter reads an infinite or O.L. reading on the auto range setting. What is likely to be the problem?

Short to the ground

Shorted

Grounded

Open

Correct! Wrong!

The unit and symbol for voltage is:

The unit and symbol for current is:

The unit and symbol for resistance is:

The unit and symbol for power is:

The concept of electron flow on a conductor can best be described as:

Resistance can best be described as:

Voltage can best be described as:

Choose a good conductor from the list below:

Choose a good semi-conductor from the list below:

Choose a good insulator from the list below.

The magnetic force which exists between any two objects that are similarly charged is:

The magnetic force which exists between any two objects that are oppositely charged is:

A lead-acid storage battery is an example of which method of producing electricity?

An alternator or a generator would be good examples of which method of producing electricity?

A good example of mutual induction in an automobile electrical system is:

The state of the tail light switch shown is such that one of the following terms could be applied to this circuit:

Which of the following is closer to the description of a series circuit?

Calculate the total resistance of three resistors which are 60 ohms, 60 ohms and 15 ohms connected in parallel.

Calculate the current flowing in a circuit if the load is three resistors of 150 ohms, 450 ohms, and 120 ohms, connected in series to a 24 volt supply:

If the supply voltage is 12 volts, the current flow is 8 amps, what is the resistance?

Load devices are normally connected in parallel so that:

Which of the following correctly represents the magnetic laws of attraction and repulsion?

Relays and solenoids all depend upon the principle of:

The magnetic field (EMF) that is found near a current-carrying conductor moves:

The rule that determines the direction of the magnetic field of a current-carrying conductor is:

How can a current-carrying wire be used to form a practical electromagnetic?

What advantages do electromagnets have over permanent magnets?

What determines the polarity of an electromagnet?

Two coils are wound in the same direction, each with the same number of turns and are connected to the same source. One coil has an air core and the other an iron core. The iron core causes:

To identify an electrical meter which is to be used to measure resistance, the meter face will be marked:

A milli volt is:

Basic ammeters are connected in _________________ with the circuit:

To correctly measure the potential difference across a resistor in a circuit, a voltmeter is connected:

If an analog ohmmeter is manually set before use to read below zero, them in use the meter will read:

Calculate the value of the resistance in an engine''s block heater circuit if the ammeter reads 7.5 amperes and the voltmeter reads 120 volts.

Electrical current is describe as the flow of tiny particles called:

1. Magnets can cause electrons to flow in a conductor. 2. Electron flow in a conductor can produce magnetism. Of these two statements:

If excessive current flows through a fuse, the metal strip melts and:

Equipment marker lights are wired in series.

A dim light on a vehicle may be caused by a poor ground.

Voltage drop in a circuit may be caused by:

When disconnecting a battery from a charger you should always:

Series circuits have ____________ path for current flow.

Each resistor in a series circuit will cause a ____________ drop across itself:

The voltage drop across resistors in a basic parallel circuit will ____________ the battery voltage.

The force needed to cause current to flow in a circuit is called:

An electromagnet''s strength may be increased by:

If resistance is doubled and the voltage remains the same:

A short can be considered to be "copper to copper" in a circuit.

While testing a solenoid coil, an ohmmeter reads an infinite or O.L. reading on the auto range setting. What is likely to be the problem?

Success!

Heavy-Duty Mechanic - Trucks & Equipment