Chapter 3.2 - 'Electric Current and Circuits' Flashcards
State what ‘a flow of electric charge’ is formally known as.
Current.
Define under what circumstance in a circuit will current flow.
When the circuit forms a continuous loop from one terminal to the other.
State what a resistor does.
Reduce current flow, and, at the same time, act to lower voltage levels within circuits.
State what a fuse is.
A short length of wire designed to melt and separate in the event of excessive current.
State the direction of flow in conventional currents.
Positive to negative.
How is conventional current indicated?
A small arrow and the symbol I.
State wether electrons are used, lost or conserved.
Electrons are conserved at all points in a circuit, they are not used up or lost when a current flows around a circuit.
Define current.
The amount of charge (in coulombs) that passes through a point in a conductor per second.
I=Q/t
Where I is the current in amperes.
Q is the amount of charge in coloumbs.
t is the number of seconds that have passed.
What is the ‘water model’?
The comparison of the current in a circuit to water being pumped around a pipe system.
What is the ‘Bicycle chain model’?
The comparison of the current in a circuit to the motion of a bicycle chain.
