Topic 2a - circuits (1. circuits, currents and potential difference) Flashcards
1
Q
what determines if a circuit is complete
A
if you can follow the wire from one end of the battery or power supply to the other end.
2
Q
what is a voltmeter
A
measures the potential difference. always connected across from the component also known as parallel.
3
Q
what is an ammeter
A
measures current. always connected in line with a component, this is known as in series.
4
Q
what is the current
A
the flow of electric charge. Cells and other power supplies always have a positive and negative terminal. current flows from + to -.
5
Q
what is the charge flow
A
the size of the current is the rate of flow of charge.
6
Q
what is the formula for charge flow
A
Q = It Q = charge flow ( coulombs, C ) I = current (amperes , A) t = time (seconds, s)
7
Q
what is potential difference
A
driving force that pushes the charge around
