Electrical Systems/ Fundamentals Flashcards
What is matter
Anything that occupies space in liquid, solid or gas form
In simple terms, what is electricity
It is the flow of electrons from one atom to another
What charge does an electron have
Negative
What charge does a proton have
Positive
What charge does a neutron have
No charge
What is a balanced atom
An atom that contains an equal amount of protons and electrons (i.e. 7 protons, 7 electrons)
If a conductor has _________ in the valence ring, it would be considered a good conductor
3 or less Electrons
Semi conductors have _______in the valence ring
Exactly 4 Electrons
An insulator has to have ______ in the valence ring
5-8 Electrons
The bigger the gauge of a wire the : _________
The more conductive and less resistant it is
The smaller the wire is the : ______
More resistant it is
What is Conventional Theory
The theory that electrons flow from the positive side of a battery to the negative
What is Electron Theory state
That electricity flow from negative to positive sides of a battery
What is current
Intensity or amperage , flow rate
What are two effects of current flow?
Heat , Electromagnetism
What does Ohms Law state (in simple terms)
It takes 1 volt to push 1 amp through 1 ohm of resistance
What is the function of a circuit breaker?
It is meant to trip once the current is overloaded
Any fuse in any circuit should be _____ more than the designed circuit current
20% more
What does a variable resistor (Rheostat) do?
Modifies current
What does a Potentiometer do?
Varies the voltage
What is the job of a Capacitor?
- Holds/ stores electricity (Voltage)
-Will smooth out an electrical signal
Describe a relay
It is a magnetic switch that uses a movable armature to control a heavy electrical load by using a low amp electrical switch
Sending a small amount of current to a relay will : _____
Cause a large current to exit
Which side is the control side of an ISO relay?
85 and 86
What is sometimes placed in the control side of a relay to prevent voltage spikes by dissipating it?
A diode
What is referred to as a hole
The space in a valence ring where another electron can fit
What is P-Type Material
- A semi conductive material that is positive and wants negative
- Has holes for additional electrons
How is a P- Type Material produced
By doping silicon or germanium with the elements boron or indium
What is an N- type Material
- Is Negatively charged and wants positive
- A semiconductor that has excess electrons because of the impurity added
- Will repel additional electrons
How is an N- type Material Produced
By doping silicon or geranium with phosphorus, arsenic or antimony
On a diode was is the positive electrode called
An Anode
On a diode what is the negative electrode called
Cathode
When diodes operate they use ____ Volts
0.5 to 0.7
What is a Diode
An electronic device made of P and N type materials, bonded at a junction. It allows current to flow through in one direction and blocks it from going back
To have a continuous flow of electricity what three conditions must be present
- An excess of electrons in one place
- A lack of electrons in another place
- A path between the two places
On a multimeter what is the rating for high voltage
Cat 3 1000v
When measuring resistance using a ohmmeter, the circuit must be : ________________________
De-powered and the component isolated
In automotive only solder with _________
Rosin core solder or rosin paste
Batteries act as ___________
Voltage stabilizers
A battery cell is made up of : __________________
Spongy lead, lead peroxide, separators, and an electrolyte sulfuric acid mixed with water.
The negative plate in a battery cell is made of:
Spongy Lead (Pb)
The positive plate in a battery cell is made of:
Lead Peroxide (PbO2)
What is the electrolyte in a cell made up of when the battery is fully charged?
64% Water (H2O) and 36% Sulfuric acid (H2SO4)
How do batteries work?
When two dissimilar metal plates are immersed in electrolyte they create voltage
How many cells does a 12 v battery have?
6 series connected cells
What color do positive plates tend to be?
Brown
What color do negative plates tend to be?
Grey
What type of battery is better able to handle being discharged over and over
Deep Cycle Battery
The specific gravity of a fully charged electrolyte is: _______
1.260 -1.280 at 25C
What gas does a lead acid battery give off while charging?
Hydrogen
How many volts in a singular cell in a 12 v battery
2.1 Volts
What is the main advantage of a Zener Diode
Its a specially constructed diode that is designed to operate with a reverse bias current. It is perfect for voltage regulation
What is power measured in?
Watts
What happens to the battery plates and the electrolyte during discharging
The Positive and Negative plates become Lead Sulfate (PbSO4) and the electrolyte becomes Water (H2O)
What is sulfation
This happens when the lead sulfate formed on discharge crystalizes on the surface of the lead plates
What are 3 things that can cause Sulfation
Alternator not charging, short trips, battery sitting for a long period of time
What is the first and last step in disconnecting a battery
Remove neg first, connect neg last
What is a cycling battery designed to do
Produce low current for long periods of time
What is a starting battery designed to do
Produce high current for very short periods of time
Difference between wet and dry charged battery
Wet is shipped with electrolyte in it , dry is filled after shipment
Low maintenance batteries use
5% Antimony to strengthen grids
Maintenance free batteries use
Calcium
AGM stands for
Absorbed Glass Material
When hydrometer testing the specific gravity difference should not vary ______ between each cell
50 points (0.50)
A battery is considered discharged when voltage reads _______
11.9 Volts
What is the Voltage of a battery that’s state of charge is 75%
12.4
On a built in hydrometer what do the 3 different colors mean
Green/Red : Charged
Dark : Discharged
Clear : Low on electrolyte
When Heavy battery load testing how do you know the amount of load to apply
It is half the CCA rating
How do manufacturers decide a CCA rating
The number of amp load a battery will maintain at -17.8 C for 30 seconds. Volts should not fall below 7.2
CA is tested at : ______
0 C for 30 seconds and must maintain at least 7.2 V
What is the industry standard maximum milliamps that can leave a battery during a draw test
0.050 / 50 milliamps
What does PNP and NPN mean on a transistor
PNP means current is flowing from the high current side and NPN means it is flowing towards the current side
What are 3 things a transistor can do
Can act like a switch, we can verify the current and can amplify a weak signal
When current passes through a load (resistance) some _________ is used up
Voltage
What would be the result of an open circuit?
High Resistance
What would be the result of a short to ground
High Current
What would indicate a bad connection in a circuit
High Voltage drop
What does the nucleolus of an atom contain?
Protons and Neutrons
What circuit protection component is placed as close to the battery as possible?
Fuse
What is the procedure when carbon pile testing a battery
Test at half the CCA for 15 second and the voltage must not fall below 9.6 V
When checking for voltage drop across a series parallel circuit how much voltage should be used?
All of it
What is the most typical wire used in automotive?
Multi-strand copper
What would have the greatest effect on resistance of a wire?
The size of the wire
What is the formula for Watts law
P(Watts)
_______________
E (Voltage) x I (Current)
How much current will flow in a circuit with two 10-ohm resistors in series with 20V applied?
Rt: 10 + 10 = 20 OHMS LAW = V/R= 20/20 + 1 ohm
What would be the effect of adding a load in parallel to a parallel circuit?
Current flowing in the circuit would increase
What is created through induction
Voltage
What is an example of a sensor that uses induction
Wheel Speed Sensor , Crank sensor , Cam sensor
Which is the most common type of coolant or air temp sensor?
NTC
What happens to an NTC when temperature increases?
Resistance goes down
How is an ammeter connected to a circuit?
In series with the circuit turned on
How is an ohmmeter connected to a circuit?
With the circuit turned off
What would the internal impedance on a good quality multimeter be?
10 Mohms
What does an upward movement of the trace on a lab scope indicate
Increased Voltage
To measure voltage drop how must the voltmeter be connected to the circuit
In parallel with the power on
What is the formula for ohms law
V
_______
I | R
