Electricity and Circuits Flashcards
What is the equation for charge?
Charge = Current x Time (Q = IT)
How is current measured?
Using an ammeter in series with the component that is being measured.
What is potential difference?
VOLTAGE. It can be seen as ‘Pressure’ produced by the circuit’s power source that pushes current through the circuit.
How are voltage, current and resistance linked?
V = IR (voltage = current x resistance)
How do insulators and conductors work?
Insulators have very high resistance. This means current cannot flow through them easily.
Conductors have very low resistance. This means electric current can easily flow through them.
What is electric current?
The transfer of energy via wires through negatively charged electrons.
How is a voltmeter used?
A voltmeter is placed in parallel with the measured component. The voltmeter’s resistance is very high to maximise the accuracy of the reading as if current is able to flow through it the reading will change.
What happens if a component like a bulb breaks in a series circuit?
If the component no longer works, the connection will be severed and the entire circuit will break
How is current measured across a series circuit?
Wherever an ammeter is placed in a series circuit the current will always be the same.
How is potential difference measured across a series circuit?
Potential difference is shared across all components from the power source. This means the sum of voltage across all components is equal to the voltage of the power source.
How is resistance measured across a series circuit?
As all resistors are in the same loop, the values of each component’s resistance all add up to the total.
How is current measured across a parallel circuit?
Since the current splits evenly for all the paths, the current will change depending on where the ammeter is placed in the circuit.
How is voltage measured across a parallel circuit?
Voltage is the same across a parallel circuit as it is equal to the voltage across each component due to there being several paths.
What happens if a component breaks in parallel?
The circuit will still work as there are other paths for the current to take.
What equation is used to calculate power?
Power = Current X Voltage
