Electricity Flashcards
What is an LDR
dependent on light intensity in bright light resistance falls and at night resistance is higher
What is a thermistor
Temperature dependent reisitor if it’s hot then resistance is less if cold resistance increases
Explain what happens in a series circuit
If one component breaks all the components stop working
How do u work out potential difference in series circuit
Total potential difference is shared ( add them together
How to work out current in series circuit
It is equal to ammeter
How to work out reisistance in series circuit
Add up to make total resistance
What happens in a parralell circuit
If one component stops working it will not affect the others
Potential difference in parallel circuit
Equal
Current in parallel circuit
Total of all currents (added up
Resistance in parallel circuit
Adding resistance reduces total resistance
What is the blue, green and red wire
Blue. Neutral
Green earth
Red live
What does live wire do
Provides potential difference
What does neutral wire do
Completes circuit
What does earth wire do
Protection
Stops appliance coming live and Carries current if there’s a fault
What is the national grid
System of cables and transformers
Transfer electrical power from power stations to meet demands
What does step up transformer do
Increase voltage as electricity flows through cables
What does step down transformer do
Decrease potential difference to make it safe
Independent depended and control variable for resistance of wire
Length of wire
Resistance
Type of metal, diameter of wire
Independent depended and control variable of series and parallel circuits with resistor
Circuit type
Resistance
Number of resisters, type of power source
Independent depended and control variable relationships in circuits
Potential difference
Current
Number of components
How do you investigate relationships in circuits
Set up circuits and measure the current and potential difference
Draw graphs once collected
What is charge
Current flowing past a point in given time
What is a ohmic conductor graph like
Current is directly proportional to potential difference
Straight line
What is the filament lamp graph like
As current increase so does temp
Makes it harder for current to flow so graph is less steep
What is diode lamp like
Current only flows in one direction
Resistance is very high in other direction meaning no current can flow
