Topic 2 - Electricity Flashcards
What is current?
Electric current is the flow of electric charge around a circuit.
The unit of current is the ampere (A).
What is potential difference (or voltage)?
Potential difference is a measure of how much energy is transferred between two points in a circuit.
What is resistance?
Resistance is anything that slows the flow down.
Resistance is measured in ohms.
What is the equation to work out potential difference?
Potential difference(V) = Current (A) X Resistance(Ω) V=IR
V=IR
Potential difference(V) = Current (A) X Resistance(Ω)
Q=It
Charge(coulombs, C) = Current(A) X Time(s)
What is the equation to work out charge?
Charge(coulombs, C) = Current(A) X Time(s)
Q=It
What is an Ammeter?
An ammeter measures the current (in amps)
An ammeter must be placed in series
What is a Voltmeter?
A voltmeter measures the potential difference (in volts)
The voltmeter must be placed in parallel
What is a conductor?
A material which allows charge to easily move through it.
Current in a series circuit
In a series circuit, the current is the same all the way around.
How is a parallel circuit different to a series?
A parallel circuit has branches whereas a series doesn’t
Current in a parallel circuit
The current in the branches adds up to the total current leaving the cell
Potential difference in a series circuit
The total potential difference across every component is shared. Therefore if you add up the potential difference of each component it will equal the potential difference of the cell.
Potential difference in a parallel circuit
The potential difference for each branch is the same as the potential difference of the cell.
