CURRENT ELECTRICITY- ___________________We are reasonably familiar with some aspects of hooking up electrical circuits as most of us have connected wires, batteries and light bulbs.
Words associated with electricity include:
Let us go over real basics. To make "something" (refrigerator, light, computer, radio controlled car, cell phone......) turn on we need an appropriate source of electricity, metal wires insulated with plastic, a switch and the thing.
The source is________________________.
The energy is transferred to the globe or CD player where it changes to _______or _________or ___________or ______________- all forms of energy. But why is it necessary to have two wires? Surely the transfer can take place with only one wire? The answer lies in the method of transfer - the motion of electrons from high potential energy in the source to low potential energy in the source.
Because it makes a continuous loop, we call the arrangement a circuit.
The flow of electrons is called a______________, an electric current. They flow from high to low energy in response to an__________________. Like charges repel. That is precisely what is happening in the circuit, negative electrons are being repelled from the "negative terminal" of the source and subsequently attracted to the positive terminal. The source uses energy from some other means to keep the electrons flowing.
Volts ___________are used to measure the potential difference. Most small modern batteries are supposed to be 1.5 or 9 volts. A car battery is slightly over 12 volts. Our houses have 120 V. Without a__________________ _______________, there will not be a flow of electrons. Voltage can be considered the _______or _____________ of electrons. Voltmeters measure volts.
Voltage sources : ______________, _________________,_________________
Electrochemical cells changes _______________________________________.
Electric current is the amount of Charge that passes a point per second.
Symbol- SI unit – ampere
Ammeters measure amps.
______________, AC: AC is produced by a______________.
Opposition to electric flow is called resistance. Resistance is caused by _____________________.
Symbol is R.
Unit is OHM ( ).
Electric charges are slowed down by interactions with atoms in the wire.
Resistance depends on type of material
Resistance _____________________the current flow.
Variables _________________, ________________, ____________________
Conductivity depends on __________________________the electrons are held in the atoms.
A poorly conducting wire (light bulb) is said to provide ___________________in the circuit. This resistance property controls the electron flow or current.
HIGH resistance tends to mean ____________currents, LOW resistance tends to mean _____________currents for a given potential difference.
(The ultimate in high resistance is a break in the circuit, an OPEN circuit)
Ohmís Law- Current = Voltage/Resistance
Electric circuit: A complete, _____________path for an electric current.
Electric power: A measure of the rate at which electricity does ______________ or provide energy.
Power = Voltage X Current
Watts = Volts X Amperes