Homeschool Guide: These lesson plans are a guide for parents. Content may contain errors — always cross-reference with official exam board specifications.

capacitors & inductors

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4 detailed 50-minute lessons with teaching scripts, worked examples, parent guides, and assessment criteria.

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Lesson Overview

Total Lessons: 4
Tier: Foundation and Higher
Duration: 50 minutes per lesson (200 minutes total)
Exam Boards: AQA, Edexcel, OCR, Eduqas, CCEA

Learning Objectives

Prerequisites

Materials & Equipment

Lesson 1: Introduction: capacitors & inductors

Duration: 50 minutes

Starter Activity (5 minutes)

Quick Recall

Write down everything you already know about capacitors & inductors. Then check against the key terms: key terms from capacitors & inductors. Use a mini-whiteboard or paper.

Main Content (35 minutes)

Parent/Teacher Guide:
Before lesson: Read the script below. Pre-teach key vocab: key terms from capacitors & inductors.
If stuck: Re-read the revision notes (link above), then break the content into smaller steps.
Extension: See the Stretch & Challenge ideas in Lesson 4.
Teaching Script (35 mins):
Mins 0-5 - Hook: "Today: capacitors & inductors. By the end you will be able to answer exam questions on it unaided. It connects to the rest of Electronics because the ideas here recur across the spec."
Mins 5-20 - Direct Instruction: Work through the core ideas below one at a time; after each, ask your student to explain it back in their own words.
Mins 20-30 - Guided Practice: Model the worked example together, then let your student attempt the first practice question with guidance.
Mins 30-35 - Independent Practice: 2-3 practice questions from Lesson 3 below, with immediate feedback.
First Look

Start with the revision notes summary, then attempt: explain the key ideas of capacitors & inductors

Plenary (5 minutes)

Check Out

Your student states one thing they learned and one question they still have about capacitors & inductors.

Lesson 2: Core Concepts: capacitors & inductors

Duration: 50 minutes

Starter Activity (5 minutes)

Review Previous Lesson

Quick recap: write 3 key points from Lesson 1 on capacitors & inductors. Check them against the notes below.

Main Content (35 minutes)

Key Fact: Capacitance C = Q/V, measured in farads (F); a capacitor stores charge on parallel plates separated by a dielectric.
Key Fact: The energy stored in a capacitor is E = ½CV² = ½QV.
Key Fact: In an RC charging circuit, V_C rises exponentially: V_C = V_supply(1 − e^(−t/RC)).
Key Fact: The time constant τ = RC is the time for the capacitor to reach 63.2% of its final voltage when charging.
Key Fact: During discharge, V_C = V_initial × e^(−t/RC); after 5τ the capacitor is effectively fully discharged.
Key Fact: Inductance L is measured in henrys (H); an inductor stores energy in its magnetic field.

Practice (10 minutes)

Q: explain the key ideas of capacitors & inductors

Answer:

Plenary (5 minutes)

Explain Back

Your student teaches the key points back to you without looking. Fill any gaps immediately.

Lesson 3: Application: capacitors & inductors

Duration: 50 minutes

Starter Activity (5 minutes)

Quick Recall

Recall the key terms: key terms from capacitors & inductors. Define each in one sentence.

Main Content (35 minutes)

Parent/Teacher Guide: Let your student attempt each question alone first, then compare with the model answer. Award method marks for correct working even if the final answer is wrong.

Work through the practice questions on the revision notes page for this topic.

Plenary (5 minutes)

Error Review

Review any questions answered incorrectly. Identify whether the error was knowledge, method, or reading the question.

Lesson 4: Exam Practice: capacitors & inductors

Duration: 50 minutes

Starter Activity (5 minutes)

Command Words

Review what these command words require: state (one point), describe (say what happens), explain (say why), compare (both sides), evaluate (judgement).

Main Content (35 minutes)

Extended Answer

Extended question: Full-Mark Response Describe how a capacitor charges and discharges in an RC circuit, explaining the significance of the time constant. <div class="

When a capacitor charges through a resistor from a supply voltage V_s, the voltage across the capacitor rises exponentially: V_C = V_s(1 − e^(−t/RC)). The current starts at its maximum value I = V_s/R and decays exponentially. The time constant τ = RC is the time taken for the capacitor voltage to reach 63.2% of V_s. After 5τ the capacitor is effectively fully charged (~99.3%). During discharge, V_C = V_0 × e^(−t/RC), where V_0 is the initial voltage. The voltage falls to 36.8% of V_0 after one time constant and is effectively zero after 5τ. A larger R or C gives a larger time constant, meaning slower charging and discharging. The exponential behaviour occurs because the charging rate depends on the remaining voltage difference, which decreases as the capacitor charges.

Exam Tips: Always convert units: μF to F (×10⁻⁶), mH to H (×10⁻³) before substituting into formulas. | State the exponential formula before substituting values in RC circuit questions. | Remember: at t = τ, charging reaches 63.2%; after 5τ it is ~99.3% charged. | For energy calculations, use E = ½CV² for capacitors and E = ½LI² for inductors. | Sketch the exponential charging/discharging curve to support your answer when asked to describe behaviour.
Common Errors: ✗ Forgetting to convert μF or mF to farads before calculation. ✓ Always convert: 100 μF = 100 × 10⁻⁶ F. ✗ Using E = CV² instead of E = ½CV² for capacitor energy. ✓ The correct formula is E = ½CV², which includes the factor of ½. ✗ Saying a capacitor is fully charged after one time constant. ✓ After one time constant (τ), the capacitor has reached only 63.2% of its final voltage. ✗ Confusing capacitor and inductor behaviour with DC at steady state. ✓ A capacitor blocks DC at steady state; an inductor acts as a short circuit to DC at steady state.
Stretch & Challenge (Grade 8-9):
  • Synoptic links: explain how capacitors &amp; inductors connects to another Electronics topic you have studied
  • Real-world: research one real-world use or example of capacitors &amp; inductors
  • Critical: "What are the limitations of the models used in capacitors &amp; inductors?"

Plenary (5 minutes)

Assessment Criteria
  • Got it: Confident explanation + correct worked examples
  • Getting there: Main points OK, needs support with detail
  • Not yet: Confused on key concepts - re-run Lesson 2

Homework & Consolidation

Recommended Resources

🎓 Smart Lesson (Guided)