MECP Basic
In Ohm's Law, what is current symbolized as?
"A" for ampere or "I" for "intensity" of the electron flow
In Ohm's Law what symbol is used for resistance?
"R"
What is voltage?
A difference of electrical potential or "charge" between two points and is measured in volts
What is an alternator?
A mechanically driven automotive device that generates AC electricity & is rectified into DC to power the electrical accessories in the vehicle. The alternator is the primary source of vehicle power while the engine is running.
What is an arming delay?
A term used to describe the elapsed time between the moment a security system is first told to arm and the moment it is actually armed. This normally only applies to systems that are passively armed, but can apply to actively armed systems as well
What is the difference between AC & DC electrical current?
AC periodically reverses direction of electrons flowing (back and forth), while DC always flows in only one direction
What is a coulomb?
An amount of electrical charge which contains 6.24x1018 (6,240,000,000,000,000,000) electrons. One coulomb per second past a given point is equal to 1 amp of current flowing
What are ions?
Atoms with extra electrons or missing electrons
How is electrical power expressed?
In Standard International (SI) units of watts
Parallel connections carry the same voltage to each individual component within the circuit, true or false?
True
Series connections carry the same current to each individual component within the circuit, true or false
True
What is ohms law?
Uses a mathematical formula to descibe a specific and measurable relationship between voltage, current, and resistance
What is found in the outermost orbit of an atom?
Valence electrons
What are free electrons?
Valence electrons that are easiest to "break away" and change the charge of the atom left behind
What is required for current flow?
Voltage
What is a series circuit?
When circuit components are connected in a string -end to end- so there is only one way for current flow "in" and only one way for current flow "out"
What is a parallel circuit?
When circuit components are connected so that there are multiple paths for current flow in and multiple paths for current flow out
What are the basic elements in an automotive electrical circuit?
-Power/voltage source -The electrical path -The circuit protection -The control of the circuit -The loads -The electrical "return" path
How do you find the total resistance in a parallel circuit?
1 / (1/R1+1/R2+1/R3...etc)
1000 watts is equivalent to?
1kW
What symbol is used for voltage?
Commonly "E" but sometimes "V"
What is "AC"/Alternating Current?
Current that alternates polarity (or it's magnetic field) between positive and negative
What is "DC"/Direct Current?
Current that supplies power to electronic components, & is either positive or negative in polarity, but not both
What is frequency measured in?
Cycles per second, or Hertz (Hz)
What is Watt's Law?
Demonstrates the relationships between Voltage (E) and Current (I) to represent a quantity of Power (P)
What does the Law of Conservation of Energy state?
Energy consumed by any component cannot be magically destroyed or "lost". The energy consumed must be converted somehow
How is current flow measured?
In units called amperes or "amps" for short
What is the division of energies known as?
Inefficiency
What is a "short circuit"?
No resistance at all, resulting in the highest possible current flow
What are protons?
Positive charge portion of the nucleus in an atom
What is power?
The conversion of one kind of energy into another over a period of time
What is current?
The movement or "flow" of free electrons through a conductor
What are neutrons?
The neutral charge portion of the nucleus in an atom
What is resistance?
The opposition to current flow
What are electrons?
The outer parts of an atom that are negatively charged
What is rectification?
The process of turning AC into (pulsing) DC
What is the total resistance?
The sum of the resistance of each component
What is an ohm?
The unit of measurement for electrical resistance named after Georg Simon Ohm