chapter 12 and 13 test review

Insulators

•Prevents the movement of electrons, are non-metals: oil, fur, wool, silk, plastic, wood, pure water

Conductor

• Allows the movement of electrons, fair conductors: human body, earth, salt water, good conductors: metals.

Battery/Source;

•Provides chemical energy to the circuit

Load:

•Device that converts electrical energy into another form of usable energy, Example: light bus, motor

Switch:

•Device that controls the electric current, on or off

Conducting Wire;

• Join all the components of the circuit together and allow electricity to flow

Ammeter:

• A device that is used to measure electric current

• Must be in series with the load

• Always set an ammeter to the highest current setting and never touch it to avoid getting shocked.

Voltmeter:

•Used to measure potential difference

•must be connected in parallel

• There is always a drop in voltage across a load or energy source.

ohmeter;

• A device that is used to measure resistance, must be placed in parallel with a load.

Resistor:

• A device used to reduce the flow of electric current. Example: dimmer switch

Potential Difference/Voltage;

• The difference in electric potential energy measured at two different points before and after a current passes through.

Resistance;

• Refers to the ability of a conducting substance to slow down the flow of electric current

•Having resistance in a circuit decreases the amount of current

• Resistance creates heat

•The greater the resistance, the lower the current, and the warmer the material becomes when a current passes through it

Factors That Affect Resistance:

1. Length: Resistance increases when the length of the wire increases because the electrons have more wire to travel through.

2.Cross Sectional Area:When the cross sectional area of a wire increases, the electrons have more space to travel so resistance decreases. Smaller cross sectional area= higher resistance. Higher cross sectional area= lower resistance.

3. Temperature: As the temperature of the wire increases, the resistance increases.

4. Material: Some materials allow electrons to move more freely than others and have lower resistance. Conductors have cow resistance.

Fuse:

A safety mechanism on a circuit, if it overheats the circuit blows.

Renewable resource;

•Natural energy that is unlimited or can be replenished by natural processes in a relatively short period of time

Non- Renewable Resource;

•A resource that cannot be replaced as quickly as it's consumed

Alternative Energy:

•Energy from natural and renewable sources, such as solar or wind.

Ohm's Law:

voltage and current in a circuit.

•The relationship between the amount of resistance in a circuit and the voltage and current in a circuit

•If voltage increases, current increases - If voltage decreases, curvent decreases.