Electrical Fundamentals Flashcards
What is Matter?
any gas, liquid or solid that has volume & mass that takes up space.
What is in the Nucleus of an Atom?
Protons & Neutrons.
What is Electricity?
The flow of Electrons from one Atom to another.
what is a Balanced Atom?
An Atom with the same amount of Protons and Electrons.
What is a Positive Charged Ion?
An Atom that loses an Electron.
What happens to an Atom that gains an Electron?
It becomes Negatively Charged.
How many Valance Electrons does a Conductor have?
It has 3 or less.
How many Valance Electrons does an Insulator have?
It has 5 to 8.
How many Valance Electrons does a Semi-Conductor have?
Exactly 4.
What are Conductors made up of?
Copper and gold.
What material are used to make Insulators?
Plastic or Rubber.
What are Semi-Conductors made up of?
Carbon and Silicon.
What is the Conventional Theory of Electricity?
Power flows from the Positive, and returns to the Negative.
What is the Electron Theory of Electricity?
Power flows from the Negative, and returns to Positive.
What is Voltage?
The electromagnetic force and pressure of Electricity.
What is Amperage?
The current and flow rate of Electrons.
What is Resistance?
The opposing force to Voltage.
What 2 things does current flow create?
Heat and Electromagnetism.
What is the normal amount of Battery draw?
50milliamps (mA)
What is Ohms Law?
It takes 1 volt to push 1 amp through 1 ohm.
What is Power rated in?
Watts.
Chemical symbol for Electrolyte?
H2SO4
Chemical symbol for Lead Peroxide?
PBO2
What type of battery produces low amps for a long period of time?
Deep-Cycle Battery.
What is Sulfation?
Occurs when a Battery discharges to the point a Sulfate Coating hardens on the Plates.
What is the Specific Gravity of Electrolyte?
1.265 (at 26C)
How many Volts does a fully charged Cell produce?
2.1 volts.
What is Electrolyte made up of?
64% water and 36% sulfuric acid.
What are 3 purposes of a Transistor?
To amplify a weak signal,varies current and act as a switch.
What side of a Transistor has low current?
Base.
What side of a Transistor has high current?
Emitter.
How do you check for Voltage in a Circuit?
hook up the multimeter in Parallel.
How do you check for Amperage in a Circuit?
hook up the Multimeter in Series.
How do you check for Resistance in a Circuit?
de-power the circuit and isolate the component.
How many Volts is considered for a Battery to be discharged?
11.9 volts or less.
How many Volts in a fully charged Battery?
12.6 volts.
What type of Battery has its cells compressed about 20%?
Absorbed Glass Mat (AGM)
What does a Green or Red dot indicate on a built in battery hydrometer?
Fully Charged.
What does a Black or ‘dark’ dot indicate on a built in battery hydrometer?
Discharged.
What does a clear dot indicate on a built in battery hydrometer?
low on electrolytes.
What is the amount of load on a Battery during load testing?
Half (50%) of the CCA rating.
What is the safety rating level for a high voltage (1000v) Multimeter?
Cat III (3).
What is a Diode?
A one way valve for Electricity.
what is the purpose of a Clamping Diode?
Used to eliminate high voltage spikes.
what voltage does a Light Emitting Diode (LED) have?
1.5-2.2 volts.
what is the purpose of a Zener Diode?
Blocks current until certain voltage is reached.
How is the Cold Cranking Amperes (CCA) determined?
Testing battery at -17C for 30 seconds, without dropping below 7.2 volts.
How is the Cranking Amperes (CA) determined?
Testing battery at 0C for 30 seconds, without dropping below 7.2 volts.
on ISO relays, which pins are the low current (control) sides?
85 and 86.
on ISO relays, which pins are the high current (load) sides?
30 and 87 (87a).
what size fuse should be in a circuit?
20% higher then the circuit amperage.
What are the 3 types of Circuit breakers?
Manual, Mechanical and Automatic (Cycling & PTC)
how does a Cycling Circuit breaker work?
A bimetal strip that changes form when certain temperature is reached.
how does a PTC circuit breaker (Thermistor) work?
As it gets hotter, it increases resistance.
What charge does a Neutron have?
No charge.
What is a balanced Atom?
An atom with equal amount of Protons and Electrons.
The bigger the gauge of wire, the ________.
more conductive, and less resistance.
What are 2 effects of current flow?
Heat & Electromagnitism.
What does a variable resistor (Rheostat) do?
It modifies current.
What does a Potentiometer do?
It varies voltage.
What does a capacitor do?
Holds/stores voltage until needed.
What is a P-type Material?
A semi-conductive material that is positively charged.
What is a N-type Material?
A semi-conductive material that is negatively charged.
How many volts is used to operate a Diode?
0.5 to 0.7 volts.
What type of Solder is used in Automotive?
Rosin based.
How does a Battery work?
2 dissimilar metal plates are immersed in electrolyte to create voltage.
What type of battery is able to be discharged over and over again?
Deep-cycle battery.
What gas does a charging battery give off?
Hydrogen.
What are 3 things that can cause Sulfation on a car battery?
Alternator not charging, short trips and long sitting battery.
What does a low maintenance battery use?
Calcuim.
When testing with a hydrometer, what is the maximum allowed difference in specific gravity?
50 points (0.050)
What is the voltage of a 75% charged battery?
12.4 volts.
When current passes through a load (resistance), what is dropped?
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 indicates a bad connection in a circuit?
High Voltage drops.
What is the procedure when Carbon pile testing (under load)?
Test it at half the CCA for 15 seconds while not going below 9.6 volts.
When calculating the specific gravity of a substance, what is its relative density compared to?
Water.
Most common wire used in automotive?
Multi-strand copper core.
What does ‘NC’ indicate on a switch?
Normally Closed.
What type of resistor is a Rheostat?
Variable Resistor.
How many Volts are used in each load of a Parallel circuits?
All volts are used.
What happens to current flow in a parallel circuit?
It splits at each branch.
What is a SPDT switch?
Single Pole Double Throw switch?
What charge does a PNP Transistor need to “turn on”?
Negative.
Where does the current flow on a NPN Transistor?
Base to Emitter.
Where does the current flow on a PNP Transistor?
Emitter to Base.
What charge does a NPN Transistor need to “turn on”?
Positive.
0 rating on an ohm meter indicates ____________?
Perfect continuity (no resistance).
What is the formula to Watts Law?
Watts / Voltage x Amperage
What is the formula to Ohms Law?
Voltage / Amperage x Resistance
what does AGM mean?
Absorbed Glass Matt.
