Test Study Guide Flashcards
Ohms Law
I=E/R,
E=IxR
Watts Law, Law of Power
P=IxE
Kilowatt Hour
A unit of power times Time
Electricity
Electron, electronics are English words that come from a word with a greek background, Elektron. the literal translation: “To be like amber”
Direction of Electron flow
outside the battery the current flows from negative to positive. Inside the battery, electrons move from positive to negative.
Conventional current flow
Current flowing from positive to negative
Electron current flow
Current flows from negative to positive.
A negative charge is an accumulation of electrons, which flows to the positive (absence of electrons)
Circuit
A path for current to flow from a source through conductors, to a device, and then back to source.
Closed Circuit
A complete path for current to flow in a circuit.
Open Circuit
A break in a circuit that causes electrons to stop flowing. Voltage still exists across the circuit. (Ex an off switch.)
Short Circuit
The current has found a shorter or alternate path back to source.
to measure voltage
measure parallel
to measure amperage
measure in series
Watt
the amount of work being done per unit of time.
The simplest form of any matter is called an
element
Atom
the smallest piece of an element that has all the characteristics of that element.
Atoms have three main parts:
Protons, Neutrons, Electrons.
Smaller subatomic particles of the proton and neutron are called:
Quarks
Charges of atomic particles
Electrons have a negative charge
Protons have a positive charge
Neutrons have a neutral charge.
You can tell the element by the number of
positive charges, or protons in the atoms nucleus.
Electricity flows from
an excess to a deficiency
forces of attraction
unlike charges attract,
like charges repell
Valence ring
The outer ring of electrons that can contain a maximum of 8 electrons.
Conductor
A material that has 1 or 2 valence electrons in the outer ring which can easily give or receive electrons from flow.
Insulator
A material that has 7 or 8 valence electrons in the outer ring which resist giving or receiving electrons from flow
Semi-conductor
A material that has 4 valence electrons in the outer ring which falls in between a conductor and an insulator.
Voltage Drop
2x(KL/CM)xI
2KLI/CM
Specific Resistance of copper alu
Copper 10.4
Alu 17.7
Resistance of a conductor
R= KL/CM
Forces that produce electricity
Friction heat chemical pressure light magnetism
Forces that electricity can produce
Chemical action heat pressure lights magnetic fields.