ELECTRICITY GCSE - AQA QUESTION AND ANSWERS LATEST
UPDATE
Why is the current provided by cell called a direct current?
Only flows in One Direction
What is alternating current?
Current that repeatedly reverses direction
What kind of current is supplied by main electricity supply
Alternating current
What is the frequency and voltage of mains electricity?
50 Hz 230 V
What colours are the live wire?
Brown
What colour is the neural wire?
Blue
What colour is is the Earth wire?
Green
What is the function of the live wire in a three core cable?
Carries the alternating potential difference from the supply
What is the function of the earth wire in a three core cable?
Safety wire to stop appliances becoming live
Why is the function of the neutral wire
Complete the circuit
When is the current in the wire?
When there is a fault
Why is the live wire dangerous?
Provide a large PD that would cause a large current to flow through the person if they
touched it
What is the national grid?
Nationwide network cables and transformers that link power stations to customers
What are step-up transformers used for in the National Grid?
Increase the PD from power stations to transmissions cables
What are stepdown transformers used for in the national grid?
Decrease the PD from transmission cables to the main supplies in the building so that is
safe to use
How does having a large potential difference in the transmission cables help the
national grid in efficient way to trans energy?
Large PG means that small current is needed to transfer the same amount power small
current and transmission cables means that less electrical power is wasted due heating
What two things does energy transfer to an appliance depend on?
Power of appliance and time it switched on for
What are the units for power?
Watts
What is the units for current
UPDATE
Why is the current provided by cell called a direct current?
Only flows in One Direction
What is alternating current?
Current that repeatedly reverses direction
What kind of current is supplied by main electricity supply
Alternating current
What is the frequency and voltage of mains electricity?
50 Hz 230 V
What colours are the live wire?
Brown
What colour is the neural wire?
Blue
What colour is is the Earth wire?
Green
What is the function of the live wire in a three core cable?
Carries the alternating potential difference from the supply
What is the function of the earth wire in a three core cable?
Safety wire to stop appliances becoming live
Why is the function of the neutral wire
Complete the circuit
When is the current in the wire?
When there is a fault
Why is the live wire dangerous?
Provide a large PD that would cause a large current to flow through the person if they
touched it
What is the national grid?
Nationwide network cables and transformers that link power stations to customers
What are step-up transformers used for in the National Grid?
Increase the PD from power stations to transmissions cables
What are stepdown transformers used for in the national grid?
Decrease the PD from transmission cables to the main supplies in the building so that is
safe to use
How does having a large potential difference in the transmission cables help the
national grid in efficient way to trans energy?
Large PG means that small current is needed to transfer the same amount power small
current and transmission cables means that less electrical power is wasted due heating
What two things does energy transfer to an appliance depend on?
Power of appliance and time it switched on for
What are the units for power?
Watts
What is the units for current
