B.5.9—Current and charge flow Topic Practice
B.5.9—Current and charge flow Topic Practice
Practise calculating current from charge flow and linking microscopic charge-carrier models to drift speed, electron number and current density.
How this is tested
- calculate current from moving charge using I = ΔQ/Δt, including surface charge or discharge data
- apply I = nqAvd to compare drift speeds when wire area changes but current stays the same
- distinguish charge flow in metals and liquids by adding contributions from opposite-moving ions to the current