Electricity Quiz Review

Name & Describe 3 methods of charging an

object & provide example of each:Friction - electrons wiped off by

rubbing one material against anotherBalloon rubbed on hairConduction - transfer of electrons by

direct contact of a charged object to another- charged object touching electroscope

Induction - in metals, charges are rearranged by indirect contact with a charged object

BatteriesProvide electricity by converting

potential chemical energy to electrical energy

Provide direct current (DC)Parts of battery (soda battery)

Electrolytes/cellElectrodesWires

Type of current in US households

AC (alternating current)

4 things that can influence resistance of a

wireThickness

Thicker has less resistanceLength

Shorter has less resistanceMaterial

Conductors have less resistanceTemperature

Colder temperatures have less resistance

How an electroscope works

If a charged object is touched to the top of the electroscope, the charge will be transferred by conduction to the ball and down the metal rod to the foil. The foil will move apart if the object is charged since according to the Law of Electrical Charge, like will repel.

It only can tell if an object is charged, NOT if it is + or -

Explain why lightning occurs

A build of of opposite charges occurs in the clouds due to friction when the air, ice and water molecules rub together.

Positive charges build up on the top of the cloud, negative on bottom, positive charges on ground.

Electrical discharge occurs as lightning.

Why food can be used as a source of electricity

Food contains potential chemical energy (cell / electrolytes) that can be transferred to electrical energy.

You need electrodes to have a chemical reaction occur with the electrolytes to get the electrons in and out of the cell

Wire connected to the electrodes are needed to make a complete circuit.