Electricity Flashcards
Revise
How do you work out resistance?
Resistance(ohms)= voltage (v) % current (amps)
What is the unit for resistance
Ohms
Why do circuits heat up?
The collisions increase due to more current moving around the wire which causes it to create more energy and be transferred to heat energy.
Two types of circuit structure?
Parallel and series
What are some qualities of a series circuit?
Closed circuit
Single path
If blocked it will stop the circuit
What are some qualities of a parallel circuit?
Open circuit
Multiple paths
If one route is blocked the current will flow somewhere else
What is AC?
Alternating current (current is always changing from positive to negative)
What is DC?
Direct Current (cells and batteries supply this and it only goes in one direction)
What are the three types of wire?
Neutral
Earth
Live
What is the point of the Live wire
CarrY alternating current
What is the point of a neutral wire
Complete the circuit
What is the point of an earth wire
Safety wire to prevent the live from getting to dangerous by transferring electricity to the ground where it diffuses safely
What is power (electricity)
The amount of energy transferred per second
What do transformers step up/down?
Voltage
Why do we want less current in transformers?
To prevent them melting the wires and not to waste energy
Why do step up transformers increase voltage?
To increase the amount of electricity that can be transferred at a time
Why do step down transformers reduce voltage
To make it safe for homes as most home appliances only require low voltage
What is static charge?
Transfer of electrons form one material to another
What happens when two insulators rub against each other?
They transfer electrons and create a positive and negative charge which creates an electrical field
Can charge be created?
No it is only moved form one object to another
What is the equation for Power?
Power(watts) = Current (amps) x Voltage (V)
OR
power(watts) = Current 2 (amps) x resistance (ohms)
