Mains Electricity

Question 1

what is the unit for an ohm?

Answer 1

Ω

Question 2

what are some hazards of electricity?

Answer 2

frayed cables
damages plugs
water around sockets
pushing metal objects into sockets

Question 3

what is the use of double insolation?

Answer 3

you protect the bare wire from coming into contact with another wire that could cause a short circuit or with the metal case and cause an electric shock.

Question 4

what is the use of earthing?

Answer 4

it is a safety wire with a very low resistance so if a wire comes loose and touches a metal casing for example then a person touches it the current will flow through the person if there is no earth wire.

Question 5

what is the use of fuses?

Answer 5

if something goes wrong and the wires touch eachother for example then the current will increase as it is short circuit ed and the fuse will get burned out due to the increases current melting the wire in the fuse.

Question 6

what is the use of circuit breakers?

Answer 6

they break the circuit if there is a fault so the current stops flowing.

Question 7

is mains a.c or d.c?

Answer 7

a.c because it can easily be converted to higher and lower voltages by a transformer.

Question 8

what is the difference between a.c and d.c?

Answer 8

a.c is alternating current ( the current changes direction periodically) and is easy to change the voltage and d.c is direct current.