Electricity Flashcards
What is required for electrical charge to flow through a closed circuit?
A source of potential difference.
What components change resistance as the current changes?
Lamps, diodes, thermistors and LDRs.
What happens to a thermistor as the temperature increases?
The resistance decreases.
What happens to an LDR as the light intensity increases?
The resistance decreases.
What are the two ways of joining electrical components?
In series and in parallel.
How is the current shared between components in series?
It is the same.
How is the total potential difference shared between components in series?
It is shared between components.
How do you find the resistance of a series circuit?
Add the resistance of each component.
What is the Hz and voltage of mains electricity supply?
230V, 50Hz.
What colour is the live wire and what does it carry?
It is brown and carries the alternating current from the supply.
What colour is the neutral wire and what does it do?
It is blue and completes the circuit.
What colour is the earth wire and what does it do?
It is green and yellow and acts as a safety wire to stop the appliance becoming live.
Why is a live wire dangerous even if the switch is open?
If the circuit becomes complete, a voltage would start and can electrocute someone.
Why is providing a connection between the live wire and earth wire dangerous?
It would make a complete circuit from mains supply to the ground, likely causing a shock or fire.
