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

operational amplifiers

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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: operational amplifiers

Duration: 50 minutes

Starter Activity (5 minutes)

Quick Recall

Write down everything you already know about operational amplifiers. Then check against the key terms: key terms from operational amplifiers. 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 operational amplifiers.
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: operational amplifiers. 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 operational amplifiers

Plenary (5 minutes)

Check Out

Your student states one thing they learned and one question they still have about operational amplifiers.

Lesson 2: Core Concepts: operational amplifiers

Duration: 50 minutes

Starter Activity (5 minutes)

Review Previous Lesson

Quick recap: write 3 key points from Lesson 1 on operational amplifiers. Check them against the notes below.

Main Content (35 minutes)

Key Fact: An operational amplifier (op-amp) is a high-gain differential amplifier with two inputs: inverting (−) and non-inverting (+).
Key Fact: The ideal op-amp has infinite open-loop gain, infinite input impedance, zero output impedance and infinite bandwidth.
Key Fact: A real op-amp has very high but finite open-loop gain (typically 10⁵ to 10⁶), high input impedance and low output impedance.
Key Fact: Negative feedback is used to control gain and improve stability; it reduces overall gain to a predictable value set by external components.
Key Fact: The inverting amplifier configuration has the input signal applied to the inverting input via Rin with feedback resistor Rf from output to inverting input.
Key Fact: Gain of an inverting amplifier: Av = −Rf/Rin; the output is 180° out of phase with the input.

Practice (10 minutes)

Q: explain the key ideas of operational amplifiers

Answer:

Plenary (5 minutes)

Explain Back

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

Lesson 3: Application: operational amplifiers

Duration: 50 minutes

Starter Activity (5 minutes)

Quick Recall

Recall the key terms: key terms from operational amplifiers. 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: operational amplifiers

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 the characteristics of an ideal op-amp and explain how negative feedback is used in both inverting and non-inverting amplifier configurations. <div class="

An ideal op-amp has infinite open-loop gain, infinite input impedance, zero output impedance and infinite bandwidth. In practice, real op-amps have very high gain (10⁵–10⁶) and input impedance, with low output impedance. In an inverting amplifier, the input signal is applied through Rin to the inverting input, with Rf providing negative feedback from output to inverting input; the non-inverting input is grounded. Due to the virtual earth principle, both inputs sit at approximately 0 V, so gain is Av = −Rf/Rin. In a non-inverting amplifier, the input goes to the non-inverting input, and a fraction of the output is fed back to the inverting input via a voltage divider (Rf and R1); gain is Av = 1 + Rf/R1. Negative feedback in both configurations stabilises the gain, makes it dependent on resistor values rather than the op-amp's internal characteristics, increases bandwidth and reduces distortion.

Exam Tips: Always show the formula before substituting values: Av = −Rf/Rin for inverting, Av = 1 + Rf/R1 for non-inverting. | Remember the minus sign for inverting amplifier gain — the output is phase-inverted. | When asked about ideal op-amp properties, list at least two: infinite gain, infinite input impedance, zero output impedance. | Draw the op-amp circuit diagram with correct input labels: (−) for inverting, (+) for non-inverting. | State the virtual earth principle when explaining how an inverting amplifier works.
Common Errors: ✗ Forgetting the minus sign in the inverting amplifier gain formula. ✓ Av = −Rf/Rin; the negative sign indicates 180° phase inversion. ✗ Using Av = −Rf/Rin for a non-inverting amplifier. ✓ Non-inverting gain is Av = 1 + Rf/R1; there is no minus sign. ✗ Assuming op-amp gain is the same with and without feedback. ✓ Open-loop gain is very high (10⁵+); closed-loop gain with feedback is set by resistor ratios. ✗ Confusing the inverting (−) and non-inverting (+) input symbols. ✓ The minus sign denotes the inverting input; the plus sign denotes the non-inverting input.
Stretch & Challenge (Grade 8-9):
  • Synoptic links: explain how operational amplifiers connects to another Electronics topic you have studied
  • Real-world: research one real-world use or example of operational amplifiers
  • Critical: "What are the limitations of the models used in operational amplifiers?"

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)