Skip to content
Marlbridge

AP® Physics 2: Algebra-Based · Unit 11 · Topic 11.1

Electric Current: Topic Checklist (Physics 2 11.1)

Specific “I can…” statements for electric current, each linked to the guide section and practice question that shows whether you can really do it.

Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.

Understanding

  • I can define current as the rate at which charge passes through a cross-section of a conductor, and give its unit. (Guide: “What current measures”; Practice Q1)
  • I can explain that a source keeps a potential difference (emf) across a circuit, and that this is what makes charge move. (Guide: “What makes charge move”)
  • I can explain that the carriers are already in the wire and the source supplies energy, not charge. (Guide: “What makes charge move”; Practice Q7c)
  • I can explain why zero current does not mean the charge carriers are at rest. (Guide: “Random motion and drift”; Practice Q2, Q7d)
  • I can explain why current is a scalar even though it has a direction along a wire. (Guide: “Which way is the current?”)

Calculation and skills

  • I can use I = ΔQ/Δt to find current, charge or time, converting minutes and prefixes correctly. (Guide: Worked example 1; Practice Q1, Q4)
  • I can find the number of electrons or ions that carry a given charge. (Guide: Worked example 1; Practice Q4, Q5d)
  • I can sketch a current–time graph and find the charge from the area under it, and the average current. (Guide: Worked example 2; Practice Q5)
  • I can find the total current when positive and negative carriers move in opposite directions. (Guide: Worked example 3; Practice Q6)

Reasoning

  • I can give the direction of conventional current from the motion of electrons, and the other way round. (Guide: Figure 1; Practice Q3, Q7b)
  • I can use the direction carriers move to decide which end of a conductor is at the higher potential. (Practice Q6a)
  • I can justify, using conservation of charge, why the current is the same on both sides of a lamp. (Practice Q7a)
  • I can use the drift speed to explain why a lamp lights almost instantly even though electrons drift slowly. (Guide: “Random motion and drift”; Practice Q7c)

All ticked? Move on to Topic 11.2, Simple Circuits, or return to the course roadmap.

AP® and Advanced Placement® are trademarks registered by the College Board, which is not affiliated with, and does not endorse, this website. Marlbridge is an independent tuition provider. It is not an authorized AP course provider, an AP school or an exam centre, and these resources are not official College Board materials. Reading them or doing simulations does not meet the laboratory requirement of an AP science course.