ELECTRICAL CIRCUITS

A Circuit: 	A never ending, looped pathway for electrons.
Any break in the circuit will prevent electrons from flowing through it.

We need some way to push the electrons around the circuit…. BATTERY!

A battery has two points for electrical contact negative end (black) and a positive end (red)

Since electrons have a negative charge, the negative end is where the electrons originate, then they flow through the circuit and return to the positive end.
Electrons are pushed out of the negative end of the battery.

Connecting both ends of a battery together with one wire is a bad idea.
It will cause a “short circuit”, it may release too much energy, usually in the form of heat (explosion!)
Circuits are designed to release this energy in a controlled manner.

Sometimes we add resistors so that we don’t create a short circuit or explode one of our lights.

Any break in the circuit will stop the flow of electrons.

Sometimes we add switches to our circuits so that we can control the flow…
An “open switch” does not allow electrons though, a “closed switch” does (weird??)

CIRCUITS IN SERIES VS CIRCUITS IN PARRALLEL

A series circuit:
All components have to be working for the circuit to be complete
All components share the voltage equally (2 bulbs connected to a 9V battery would shine with 4.5 V each) 

A parallel circuit: 
Not all components need to be working for the circuit to be complete
All components have the same voltage (2 bulbs connected to a 9V battery would shine with 9 V each)
**Uses more energy.