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some common alternative sources of electricity
Wind, sun, biofuels, water, and waves
electric current
the amount of charge flowing per unit time.
whenever there is a potential difference (voltage) between the terminals of a source.
when does charges flow
electricity
flow of charges in a conductor
charges
It usually progresses from a positive to a negative terminal.
current
flow of electric charge.
ampere
SI unit of electric current
current
In electric circuits this charge is often carried by moving electrons in a wire
voltage
the potential to flow, Increases the further distance up.
resistance
the pushing back against flow, decreases if pipe width is bigger.
current
the actual flow, increases when voltage is high and resistance is low.
thickness
length
material
temperature
Four components change the resistance of a wire
Resistance
Less ____ Allows More Current
Increases
______Resistance (Less Current)
thinner the wire
The ___________ the less electrons can flow
longer the wire
The ____________ the more distance from point A to point B
lower conduction
The material of the wire, the ____________, the harder it is for electrons to flow.
Higher temperatures
____________ increase resistance in a wire.
Decreases
_______ Resistance (More Current)
wider the wire
The ____________ the more electrons can flow
shorter the wire
The _____________ the less distance from point A to point B
higher conduction
The material of the wire, the ___________, the easier it is for electrons to flow
silver
copper
gold
aluminum
Top Conductive Metal Elements
Lower temperatures
___________decrease resistance
battery
fuse
load
resistor
open switch
closed switch
Common Symbols Used In A Circuit
battery
A long line next to a shorter line.
positive terminal (cathode)
long line represents what
negatuve terminal (anode)
short line represents what
battery
provides the source of electrons in a circuit.
fuse
This is a safety device added to a circuit.
fuse
This protects from fire or equipment damage that could result from an excessive current.
circuit breaker
safety device to protect from damage including fire with the same purpose as a fuse.
circuit breaker
When too much current is present the circuit will open. This will be manually reset to close the circuit again.
load
This is any device the circuit can power
load
It can be a light, speaker, toaster oven, or anything else.
resistor
This is a device specialized to slow down the current in a wire.
open switch
The symbol it two dots with a slanted open wire in the middle showing an open circuit.
closed switch
The symbol is two dots with a wire still connected in the middle showing a closed circuit.
closed
A circuit must be ______to have electrons flow (current) and the load on
off
A open circuit is ____
on
A closed circuit is _____
electric field
A potential difference (V) between two points creates an _______
circuit
An electric field moves through a ______setting electrons in motion
electron drift.
Electrons move slowly bouncing around in many directions as they gradually follow the direction of current. This random patter is called
heat
always a side effect of electric current
electron drift
why is Heat always a side effect of electric current
rectification
The process of turning AC into DC
rectification
can be done using diodes
diodes
electronic components that allow a flow to occur one way but not the other.
direct cuurent DC
an electric current that is uni-directional, so the flow of charge is always in the same direction.
alternating current AC
flow of electric charge that periodically reverses.
battery
always provides a direct current with conventional current flowing from the positive terminal to the negative.
common outlet
will have alternating current when you plug an appliance into the wall. Often there will be a rectifier to convert alternating current (AC) into direct current (DC) as many appliances require DC current.
Benjamin Franklin
, introduced the terms positive and negative charges
conventional current
electric current was defined as the flow of positive charges from the positive terminal to the negative terminal of a source of voltage.
benjamin franklin
introduced the words plus, minus, positive, negative, charge, and battery.
electron current
current in a metallic conductor is actually a flow of electrons from the negative terminal to the positive terminal.
conventional current
Electron current is equivalent to the ___________ flowing in the opposite direction
electric currrent (I)
the amount of charge passing through any point in a conductor per unit time.
ampere
was considerd “the Isaac Newton of electricity”
André Marie Ampére
He was the first to describe current as a continuous flow of electricity along wire
André Marie Ampére
The unit ampre is named after the French scientist and mathematician,
André Marie Ampére
He found ed the science of electrodynamics-the study of charges in motion
Electrical resistance, or simply resistance,
the opposition of material to the flow of electric current.
ohm (Ω)
The SI unit of resistance
Georg Simon Ohm
ohm was named after who
resistors
Most electrical connection use devices called ____ to regulate the amount of current passing through a conductor.
fixed
variable
Resistance values of the resistors may be ____ or _______.
variable resistances
Potentiometers, light dependent resistors, thermistors, and wire-round rheostats
fixed resistance values
Metallized film resistors, carbon resistors, wire-wound resistors, and chip resistors
metal film resistors
have a thin metal layer as resistive element on a non-conducting body.
metal film resistors
They are among the most common types of axial resistors.
carbon resistors
contain both solid carbon (graphite) and a clay additive to help with durability and were more common prior to the early 1970s.
wire-wound resistor
an electrical passive component that limits current. The resistive element is an insulated metallic wire that is wound around a core of nonconductive material
chip resistor
a passive electronic component that limits the flow of Direct Current (DC) and Alternating Current (AC)
chip resistor
Among its properties is to lower the voltage or maintain the current constant inside an electronic circuit
INTERNATIONAL ELECTROTECHNICAL COMMISSION (IEC)
AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI)
Two sets of symbols are used to represent resistors
6 or 7
how many bands colors does resistor have
electrodes and electrolytes
A battery consists of cells. Each cell basically consists of two _________
internal resistance of a cell
Cells also offer low resistance to electric current
r
Internal resistance is usually represented by
internal resistance
because of this, the potential difference across the terminals of cell when current is flowing through it is less than when there is no current.
electromotive force
potential difference across its terminals when no current is flowing called
electromotive force
the voltage indicated on a battery.
terminal voltage (TV)
The potential difference across the terminals of a cell when current (I) flows through
alessandro volta
invented the first electron cell in 1799
voltaic pile
It consisted of alternating disks made of zinc and silver with a piece of cloth soaked in salt solution between them.
voltaic pile
formed of the basis of modern cells and batteries such as the dry cells, storage battery, and nickel-cadmium cell.
Note 
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