Electricity Flashcards
when we rub a balloon against our sweater then put it to the wall, why does it stick?
because the sweater gets a negative charge, and the negatively charged particles repel in the balloon and wall, so overall they get attracted to each other as the part of the wall closer to the balloon is more positively charged
what kind of material can be charged through friction?
insulating material
rules of charges
- every object has positive and negative charges
- like charges repel, unlike charges attract
- only negative charges move from one object to another
why doesn’t a metal rod hold onto its charge?
because it isn’t insulating and conducts electricity
what is a fuse
thin piece of metal with a low melting point usually inside a cartridge
what does a fuse do?
it’s a safety device, it melts if the current becomes too high and so breaks the circuit, preventing an electrical fire
what is a plug composed of?
earth wire, live wire, neutral wire, fuse, outer insulation, cable grip
what is double insulation?
some appliances (e.g. vacuum cleaners and electric drills do not have an earth wire; because they have plastic casings, or they have been designed so that the live wire cannot touch the casing
what does double insulation do?
the casing cannot give an electric shock, even if the wires inside become loose
what is static electricity?
means that electricity stays on the material and doesn’t move, builds up when electrons are rubbed off one material onto another
using static electricity in everyday life
applying paint evenly, electrostatic smoke precipitator
