Flashcards in Current and Potential Difference Deck (7):
What is current?
The flow of electric charge round the circuit. Current will only flow through a component if there is a potential difference across that component. Unit: Ampere, A
What is Potential difference?
(same as voltage) The driving force that pushes the current around. Unit Volt, V
What is resistance?
Anything in the circuit which slows the flow down. Unit:, ohm, Ω
The greater the resistance across a [ ], the [ ] the current that flows (for a given [ ] across the component)
Charge / Time
Current: Amperes (A)
Charge: Coulombs (C)
Time: seconds (s)
A battery charger passes a current of 2.5 A through a cell over a period of 4 hours. How much charge does the charger transfer to the cell altogether?
Q = It
= 2.5 * (4*60*60)
= 360,000 C (or 36kC)