P2 - Electricity Flashcards
What is meant by a series circuit?
It has no branches.
Current can only flow in one path around the circuit.
What is meant by an electric current?
A flow of electric charge around a circuit.
Describe the pattern of current flow in a series circuit
Current is never used up in a circuit.
The current is the same all the way around.
What is meant by a parallel circuit?
A parallel circuit contains branches.
The current splits across the branches.
Describe the pattern of current flow in a parallel circuit
Some of the current passes through all branches.
The current in the branches adds up to the total current leaving the cell.
What is meant by potential difference?
A potential difference of 1 volt tells us that 1 joule of energy is transferred for each coulomb of charge that is moving through the circuit.
How can we measure potential difference?
Place a voltmeter across the component of the circuit
Describe potential difference in series circuits
The potential difference is split across the components.
The total p. d. across both lamps is the same as the p. d. across the cell.
Describe how potential difference changes in parallel circuits
For components connected in parallel, the potential difference across each component is the same.
What is meant by a battery?
2 or more cells connected together.
Cells in a battery must be connected in the same direction.
How do we calculate the potential difference produced by a battery?
The p.d. of the cells adds up to give the p. d. of the battery.
Electrical charge is measured in…
Coulombs. (C)
A current of 1 Amp = 1 (..) of (..) flowing per second
1 coulomb of charge flowing per second
The size of the electrical current is the (..) of electrical charge
(Rate of flow)
What is meant by resistance?
The resistance tells us the potential difference required to drive a current through a component.
(How much energy is required to push a coulomb of charge through)
What is meant by a resistor?
An electrical component that restricts the flow of electrical charge.
Describe the current/ potential difference graph for an ohmic conductor
Current through a resistor is directly proportional to the potential difference.
(The resistance is constant & does not change if we increase the current)
The resistance will only stay constant if…
The temperature is constant.
