Section 2 Flashcards
Why must appliances with metal cases be earthed?
To reduce the danger of electric shock.
What does earthing mean?
The case must be attached to an earth wire.
What does double insulated mean?
The appliance has a plastic casing and no metal parts showing.
What is an advantage of a circuit breaker over a fuse?
They can be easily reset by flicking a switch on the device. This makes them more convenient than fuses which have to be replaced once they’ve melted.
What is current?
The rate of flow of charge round the circuit.
What is voltage?
The driving force that pushes the current around.
What is resistance?
Anything in the circuit which slows the flow down.
What is resistance measured in?
Ohms.
If you increase the voltage …
… more current will flow.
if you increase the resistance …
… less current will flow.
Where must an ammeter be placed in a circuit?
In series.
Where must the voltmeter be placed?
In parallel around the component under test.
What is direct current?
Current flowing in he same direction.
What is alternative current?
Current that changes direction continuously.
What is a benefit of using a parallel circuit instead of series?
Components can be operated separately.
