8 Electricity Flashcards
What are the two different types of electric charge?
positive (+) and negative (-)
What is static electricity?
A build-up of electrical charge on an object
How do like charges interact?
They repel
How do unlike charges interact?
They attract
How does distance affect the force between charges?
The closer the charges, the greater the force between them
What charge do electrons have?
Negative (-) charge
What charge do protons have?
Positive (+) charge
What charge do neutrons have?
Neutrons have no charge
What does rubbing materials do in relation to electric charge?
It separates charges already there
What are conductors?
Materials that let electrons pass through them
Why do conductors lose charge almost immediately after gaining it?
Electrons can easily flow through them until balance is restored
Why are insulators easy to charge by rubbing?
Any electrons that get transferred tend to stay
What are examples of conductors?
Silver, copper, aluminium, carbon
What are examples of insulators?
PVC, polythene, perspex, glass, rubber, dry air
What are semiconductors?
Materials which are poor conductors when cold, but better conductors when warm
What are examples of semiconductors?
Silicon, germanium
What happens if enough charge builds up on something?
Electrons may be pulled through the air and cause sparks
What is earthing?
Objects are connected to the ground so unwanted charge flows away
What is induction?
An uncharged object getting charges because of a charged object nearby which does not actually touch it
What is the SI unit of charge?
coulomb (C)
What is a microcoulomb in coulombs?
1 µC = 10^(-6) C (one millionth of a coulomb)
How much is the charge of 1 coulomb roughly?
Equal to the charge on about 6 billion billion electrons
What are uses of electrostatic charge?
Electrostatic precipitators, photocopiers, laser printers
What is an electric field?
An area around a charged particle or object where electric charges feel a force
In electric field patterns, in which direction do the arrows go?
The direction in which the force on a positive (+) charge would act, (away from positive, towards negative charge)
When a conductor is charged up, where do the charges concentrate?
The outside
When a conductor is charged up, where do the charges concentrate the most?
The sharpest curve
What are ions?
Electrically charged atoms, or groups of atoms
What is a stream of atoms an example of, and why?
A current, as it is a flow of charge
How do atoms become ions?
They lose, or gain electrons
Without ions, what is air?
A good electrical insulator
With ions present, what is air?
A conductor
