Current and Potential Difference

Question 1

What is current?

Answer 1

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

Question 2

What is Potential difference?

Answer 2

(same as voltage) The driving force that pushes the current around. Unit Volt, V

Question 3

What is resistance?

Answer 3

Anything in the circuit which slows the flow down. Unit:, ohm, Ω

Question 4

The greater the resistance across a [ ], the [ ] the current that flows (for a given [ ] across the component)

Answer 4

component
smaller
potential difference

Question 5

Current =

Answer 5

Charge / Time
Current: Amperes (A)
Charge: Coulombs (C)
Time: seconds (s)

Question 6

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?

Answer 6

Q = It
= 2.5 * (46060)
= 360,000 C (or 36kC)

Question 7

Potential Difference =

Answer 7

Work Done / Charge
P.D: Volts, V
Work Done/Energy Transferred: joules, J
Charge: Coulomb, C