Mains electricity Flashcards
What do circuit breakers do?
break the circuit when the current is too high
what colour is the earth wire’s insulation wire?
green/yellow
what colour is the neutral wire’s insulation wire?
blue
what is the colour of the live wire’s insulation wire?
brown
what does the fuse wire do when the current exceeds a certain value?
the fuse wire melts
state the relationship between current power and voltage.
current = power/voltage
typical fuse values
3A, 5A, 13A
what do fuses use to protect appliances?
the heating effect
what do circuit breakers work via?
electro-magnetism
what do appliances with a metal case require?
Earth wire/earthing
what would happen if metal-cased appliances were not earthed?
if the live wire comes loose and touches the case, anyone touching it would get electrocuted
do plastic cased appliances need an earth wire?
no
benefit of double insulation
the outer plastic is a second insulator so even if the live wire comes loose, no current escapes
DC = ?
direct current
AC = ?
alternating current
