Topic 2 : Electricty Flashcards
What does it mean when there is a higher potential difference being moved round in a circuit?
The more energy transfers to the circuit
What is potential difference measured by?
Volts (V)
What’s another name for potential difference?
Voltage
What is resistance?
How difficult it is for current to flow
What does it mean when there is higher resistance in a circuit?
The harder it is for current to flow through the comment
What is resistance measured in?
ohms
What does the symbol I stand for?
Current
What is current measured in?
Amps (A)
What does LED stand for?
Light-emitting diode
What does LDR stand for?
Light-dependent resistor
What is the electric current?
The flow of electrical charge
What is the unit of charge?
Coulombs (C)
What is the unit of time?
Seconds (s)
What does a circuit mean?
A closed loop that an electrical current can flow through
What are the two type of circuits?
Series
Parallel
Where does electricity come from?
An ac or dc power supply
What does dc stand for?
Direct current
What is the result of of a direct current?
The current only flows in one direction
What does ac stand for?
Alternating current
What does alternating current mean?
The potential difference alternates quickly between positive and negative
What does the ac current produce?
regularly changes direction
Is mains electricity ac or dc?
ac
In the uk mains electricity has frequency and potential difference of what?
Frequency = 50 Hz
Potential difference = 230 V
What does the (brown) live wire do?
Carries the alternating potential difference from the power supply
What does the (blue) neutral wire do?
Completes the circuit
What is the (green and yellow) Earth wire?
A safety wire that prevents the case of the applicant from becoming charged
What does bigger the current mean?
The greater the power transferred
What is the national grid?
A system of cables and transformer across the country that links power station to consumers
What do the transformers do?
Change the potential difference and the current of an perri city supply
What are step-up transformers?
They increase the potential difference and decrease the current
What are the step - down transformers?
Decrease the potential difference, making it safer for consumers
What examples of domestic use of electricity?
Lighting
Heating
Cooking
