Chapter 1: Electrical Basics Flashcards
What is Electricity?
An invisible force that can produce heat, motion, light, and many other physical effects.
Electricity, electron, and electronics are English words that come from a word with a Greek background, what is that word?
Elektron, which means “to be like amber”
In the 1600’s who coined the terms electriks and non-electriks?
William Gilbert
What are Electriks and Non-Electriks?
Electriks are materials that could be charged
Non-electriks are materials that could not be charged
In 1733, Charles DuFay discovered
some charged materials would attract other objects and that other charged objects would repel different objects.
What is the purpose of Ohm’s Law?
Describes in detail the Mathematical relationship among Voltage, Current, and Resistance in a simplified form.
In Ohms Law nomenclature “I” is ________, “E” is ________ and “R” is ________
Current
Voltage
Resistance
The Letter “I” represents ______ and is evolved from the notion ?
, it is measured in ?
Current
that it was representative of the intensity of flow, measure in Amperes
The Letter “E” or “V” represents ______ and evolves from the abbreviation ? , and is measured in ?
Voltage
Electromotive Force measures in Volts
The Letter “R” represents ?, and is measured in ?
resistance to current flow in the circuit
measured in ohms
What is the basic premise/concept of Electricity?
The movement of Electrons that have been activated or energized by an external energy. That external energy is imparted to the electrons, which “flow in a conductor”. The electrons give up their energy at an electrical load as they produce heat, light, motion, etc.
How do we measure the flow of electrons?
Electrons are measure in coulombs per second at a fixed point.
What is a coulomb?
6.25 x 10^18 electrons. This is the fixed quantity of electrons that move past a certain point per second.
One coulomb is equal to how many amps?
1 amp
An Ampere is equivalent to
1 coulomb of electrons flowing past a specific point in a wire in 1 second.
What charge does an electron have?
Negative
In a battery, the negative terminal is
where there is an excess buildup of electrons due to their negative charge.
Outside the battery, the electrons travel
from the negative terminal through each circuit component and back to the positive terminal.
Inside the battery, the electrons move
from the Positive terminal to the Negative terminal.
What tool is used to measure the amount of current flow in a circuit?
An ammeter
How does an Ammeter work?
As current flows through a circuit, it will flow through the meter’s movement. The movement responds to the magnetic field created by the current flow.
When measuring with a Analog Ammeter what must you do to obtain an accurate reading, when measuring current?
Begin with the highest scale on the meter and then decrease the scale to obtain the proper reading.
What is Conventional Current Flow?
The flow of electrons from the Positive Pole to the Negative Pole of a DC source.
What is the concept of Conventional Current Flow?
An electron leaves an atom, causing the atom to become more positively charged. This creates a hole, this hole is then filled with an Electron from a neighboring atom. As electrons move in one directions, the Hole moves in the opposite direction.
Current in a conductor travels at what speed?
Less than the speed of light. Often 80%