Mains Electricity Flashcards
Fuses contain a wire that… if a large…. flows through it
Melts
Current
Current produces….., thus….the circuit.
Heat
Breaking
Give advantages of using circuit breakers instead of fuses
2
They act much quicker
Can easily be reset
Explain how the metal cased earth wire helps prevent electrocution
If a fault causes the live wire to become loose and touch the metal case, a large current flows through the case and the earth wire, into the ground, often by a metal spike.
This causes the fuse to melt, making the circuit not live.
What does double insulated mean
Anything that has a plastic casing is double insulated.
They do not contain an earth wire
So if the live wire touches the case, it does bot become “live” and the electrocution cannot occur.
What colour is the neutral wire
Brown
What colour is the live wire
Blue
What wire goes through the fuse
The live wire
Why is a wire many thin strands instead of one thicker piece
Just in case one breaks, the current will still flow. 9The current flows on the outside of the wire, so lots of strands , more current can flow.
What happens if a thin cable is used
Might overheat and melt
Give some unsafe situations with electricity
Its not going through the fuse
Water is next to electricity
Wire broken and the electricity can jump out
What is d.c
Direct current, used in battery and cells
How would you set up an experiment to measure the current rating of a fuse
Use crocodile clips to attach the fuse and in the same circuit have a variable resistor. Slowly slide it from high to low resistance. When the fuse breaks, measure the current on the ammeter,
Give the equation with power, current, voltage
P = I x V Power = Current x Voltage
What does the E stand for in E = V x I x t
Energy transferred joule
