2.2-2.6 mains electricity Flashcards
1
Q
whats the purpose of earth wires and fuses
A
-if live wire comes in contact with metal case
-flows back through earth wire
-current increases
-fuse melts
-circuit breaks
2
Q
how do you calculate power?
A
power = current x voltage
3
Q
how do you calculate energy transferred
A
energy transferred = voltage x charge
4
Q
what is the difference between a.c. and d.c.
A
a.c.:
charges that continually change direction
d.c.:
charges flowing in a single direction only
5
Q
how many volts is mains plug
A
230 v
6
Q
what is an insulator?
A
A material that doesn’t allow electrical charge to flow
7
Q
what is a double insulator?
A
when the outer parts are made out of insulater
