P 2.1 Electrical circuits Flashcards
What is an electrical current?
The rate of flow of electrons
What is the equation linking current, charge flow and time
Q = I x t
charge flow = current x time
What is the particle that carries electrical charge round a circuit
Electrons
What is potential difference
The voltage between two points that makes an electric current flow between them
What is resistance?
Resistance is restriction to the flow of current
What is the equation linking potential difference, current and resistance? (Ohm’s law)
V = IR
potential difference = current x resistance
How does increasing the resistance in a circuit affect the current flowing through a circuit?
Increasing the resistance decreases the current
Is an ammeter connected in series or parallel
Series
Is a voltmeter connected in series or parallel
Parallel across the component
Current in a series circuit
Same all round the circuit
Current in a parallel circuit
Shared along each loop
Potential difference in a series circuit
Shared by each component
Potential difference in a parallel circuit
Stays the same on each loop
Why does adding more bulbs in a series circuit cause the current to decrease
Increases resistance
What is D.C.
Direct current, e.g. batteries
Electrons flow in one direction from positive to negative
