P5 - Electricity In The Home (PAPER 1) Flashcards
What is a direct current
A current that flows in only one direction
What is an alternating current
A current that keeps reversing its direction of flow
What is a live wire
A wire that is alternately positive and negative every cycle
What is a neutral wire
A wire that is constantly at zero volts
What is the peak potential difference of an alternating current supply
The maximum voltage measured from zero volts
What is the equation for frequency
Frequency (Hz) = 1 / time taken for one cycle
What are the outer casings of plugs made from and why
Hard wearing electrical insulators because there are live wires contained within them
What colour are live, neutral and earth wires
- live - Brown
- earth - green and yellow
- neutral - blue
What are earth wires
Wires that provide electrical connection to the ground
What type of wire is connected to the longest pin of a plug
The earth wire
What is the formula that links energy and power
Power (W) = energy transferred (J) / time (s)
What is the formula for the correct rating of a fuse
Electrical power (W) / potential difference (V)
What is the formula for the electrical power supplied
Power supplies (W) = current (A) x potential difference (V)
What is the formula for the flow of electric charge
Charge flow (coulombs) = current (A) x time (s)
Where is energy transferred when charge flows through a resistor
To the resistor, heating it up
