OCR 21st century science P5

built up of static energy- caused by friction  (balloon)

electrons our scraped of one and dumped onto the other. - insulating material

leaves positive static on one and negative on other

similar charges repel   

opposite charges attract

electric current = flow of charge

electric current measured in VOLTS     e.g  V

circuit wires  are made of : metal with plastic cover

the plastic cover=  insulator ( stops the current flowing) 

battery- pushes the charge through the wires  like a pump.

current depends on voltage and resistance...

voltage = driving force that pushes current around.   units= volts aka V

resistance = stops/slows down the flow of current. units = ohms aka Ω

increase votage = more current flows

increase resistance = less current flows