P4 - Charge in Circuits Flashcards
What is current?
Current is the flow of electrical charge around a circuit, the flow of electrons.
What is current measured in ?
Amps, A.
What is the correlation between charge and current?
More charge pass around a circuit when a higher current flows.
When will current flow?
Current will only flow through a component if there is a voltage across that component ( unless that component is a super conductor ).
What is voltage?
Voltage is the driving force that pushes the current round, it like “electrical pressure”.
What is voltage measured in?
Volts, V.
What is resistance?
Resistance is anything the circuit which slows the flow down.
What is resistance measured in?
Resistance is measured in ohms.
What is the balance in a circuit?
The voltage is trying to push the current round the circuit, and the resistance is opposing it.
What decides how big the current will be?
The relative sizes of the voltage and resistance decide how big the current will be.
What happens if you increase the voltage?
More current will flow.
What happens if you increase resistance?
Less current will flow. ( Or more voltage will be needed to keep the same current flowing ).
What is required for the current to flow?
- Current only flows in a circuit as long as there is a complete loop for it to flow around, break the circuit and the current stops.
What are some safety features of a circuit?
Wire fuses and circuit breakers ( resettable fuses ) are safety features that break a circuit if there is a fault.
