Electrical Flashcards
When measuring voltage, you need to connect the voltmeter in ____ with the circuit…
Parallel
The unit for measuring current is…
Amperes
AC and DC are short for…
Alternating current and Direct current
In order to check standing voltage at a battery, what setting should your voltmeter be on?
DC volts
True or false, when measuring current with the clamp on ammeter, you must break the circuit.
False, you can not measure current if there is no flow through the circuit
True or false, it is OK to clamp more than one wire at once when you’re measuring current.
False
Using Ohm’s law, how would one find amperage?
Divide voltage by resistance
What are the 5 components necessary to create a circuit?
- Source
- Circuit protection
- Circuit control
- Load
- Ground
What is a unit of resistance?
Ohms
What is an ideal level of voltage drop?
0.00V
What is an acceptable level of voltage drop?
100mV
one horsepower is equivalent to ____ watts
746
A relay is a…
Electrically controlled switch, uses a low voltage to control a high voltage.
A type of electromotive force that causes electron flow in an alternator is called
magnetism
Generally speaking, what is the difference between relays and solenoids?
-Relays just makes the electrical connection and have very little physical movement
-Solenoids make electrical connections and also have some physical external movement. Solenoids also tend to be more robust.
there are three ways to induce voltage through magnetic induction, they are:
- Generated voltage
- Self induction
- Mutual induction
True or false, in mutual induction, coils are placed side by side.
True
In a circuit, a switch is an example of
Circuit control
when it comes to switches, DPDT stands for…
Double pole, double throw
In the presence of excessive heat, a fuse/fuseable link will…
melt and break the circuit
If a material has exactly four electrons it is considered a
Semiconductor
A material with 5 or more electrons would be considered a
insulator
Why are insulators effective?
because they limit electron flow between different materials.
Two materials that are known semiconductors are
Silicon and germanium
Electrical pressure, potential, or potential difference all refer to…
voltage
Four things that contribute to increased resistance in a circuit are…
- Corrosion
- Length of wire
- Diameter of wire
- Temperature
Optimal opperating temperature for a 12V battery is…
80 Degrees F
You need to calculate total resistance in a series circuit with multiple resistors, what formula do you use?
R1 + R2 + R3
The rule for calculating total resistance in a parallel circuit is…
1 / 1/R1 + 1/R2 + 1/R3
A common wire material is ___
Copper
Electrons generally flow around the ____ of the wire
Outside diameter
If a starter does not have a ground terminal it will be ground through
the frame
The starter pinion and ring gear ratio is about
18:1 to 20:1
The starter takes electrical energy from the ______
Battery
How does an inertia drive starter drive mechanism work?
Rotational force by the armature moves the pinion gear into the ring gear.
OCP stands for
Over crank protection
A component that protects a starter from running for too long is called
OCP - over crank protection
True or false, the alternator output is DC but the orignical source inside the alternator is AC which is converted to DC.
True
Alternators are typically mounted in two configurations, they are….
-Pad mount
-Hinge mount
Why do alternators need to have a higher voltage than the battery they are supplying?
Electrons move from areas of high concentration to areas of low concentration. If the voltages between the alternator and the battery were the same, there would be no flow.
The two types of stator configurations are…
Wye and delta
Of the two stator configurations, which is most efficient?
Delta, delta wound produces 40% more power.
One main advantage that alternators have over generators is ….
higher current output
True or false, in order to test voltage drop from your alternator, the machine needs to be running.
True
A kilowatt of power is equivalent to _____ HP
1.3, the formula for calculating this is 1000/746
How to opposite magnetic poles behave?
They attract
You’re reading a schematic and encounter ‘H14Pk’ written above a wire, what does this designation mean?
Harness, 14 gauge wire, pink in color
A material with less than 4 electrons is considered to be a good ________
Conductor
EMF is short for…
Electromotive force
The function of an insulator is to…
Prevent the free flow of electrons across a surface
Within a circuit, if resistance increases
Voltage decreases
Name a common type of connector
- Butt connector
- Ring terminal
- Blade terminal
The four terminals that you are likely to encounter on the starter are…
B - Battery
S - Start
M - Motor
G - Ground
Which starter terminal may or may not always be present?
Ground
What is the function of the starter solenoid?
It engages the starter motor to the flywheel
What is the function of the starter motor?
It drives the flywheel to crank the engine
The largest terminal on the alternator will always be…
the positive terminal
Delco-Remy style alternators use ‘1’ and ‘2’ terminals which are used for…
1 - Indicator lamp
2 - voltage sensing
What component of the alternator converts AC to DC?
Rectifier bridge
The stator is a stationary component of the alternator, what component spins inside it?
Rotor
When performing a battery test with a carbon pile, what would be considered an acceptable load to put the battery under?
Half of the batteries CCA rating