Flashcards in Mains Electricity&In the home Deck (16):
Mains supply is DC/AC ?
battery supply is DC/AC?
Mains supply is AC
Battery supply is DC
What is the U.K.'s main supply in volts and frequency?
Volts= 230 V
Frequency = 50Hz
What does an AC supply mean?
An supply means the current is constantly changing direction
What does DC supply mean?
This means that the current always flows in the same direction
If you plug in AC supply into an oscilloscope what trace will be shown on the screen?
The screen shows how the voltage of the supply changes with time. The trace goes up and down in a regular pattern.
If you plug a DC supply into an oscilloscope what trace will this show?
The trace you get is just a straight line
How do you work out the frequency?
Time period (s)
What is electric current?
Electric current is the movement of charge carriers
What colours are the neutral wire live wire and earth wire?
Earth wire = green&yellow
Neutral wire= blue
Live wire = brown
What is the earth wire used to do?
The earth wire is for protecting the wiring and for safety- it works together with a fuse to prevent fire and shocks
How does the earth wire prevent fire and shocks?
It is attached to the metal casing of the appliance and carries the electricity to the earth , away from you
Why are the metal parts of a plug made of copper or brass?
Because these are very good conductors
Why is the case, cable grip and cable installation in a socket made out of rubber or plastic?
Because these are really good insulators and flexible
Which of the live, neutral or earth wires is always at O volts?
The neutral wire( blue)
Which two wires usually carry the same current?
The live and neutral wires