Homeschool Guide: These lesson plans are a guide for parents. Content may contain errors — always cross-reference with official exam board specifications.
circuit calculation questions
FoundationHigherAll Boards
4 detailed 50-minute lessons with teaching scripts, worked examples, parent guides, and assessment criteria.
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
Explain the key ideas of circuit calculation questions
Apply circuit calculation questions to exam-style questions
Write down everything you already know about circuit calculation questions. Then check against the key terms: key terms from circuit calculation questions. 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 circuit calculation questions. 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: circuit calculation questions. 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 circuit calculation questions
Plenary (5 minutes)
Check Out
Your student states one thing they learned and one question they still have about circuit calculation questions.
Quick recap: write 3 key points from Lesson 1 on circuit calculation questions. Check them against the notes below.
Main Content (35 minutes)
Key Fact: Always write the formula first, then substitute values, then give the answer with units — this secures method marks even if the final answer is wrong.
Key Fact: Ohm's Law: V = IR can be rearranged to I = V/R or R = V/I depending on which quantity is unknown.
Key Fact: Power formulas: P = VI, P = I²R, P = V²/R — choose the one using the two known quantities.
Key Fact: For potential dividers: V_out = V_in × R2/(R1 + R2); always identify which resistor is R2 (the one V_out is measured across).
Key Fact: Convert all units to base SI before calculating: mA to A (×10⁻³), kΩ to Ω (×10³), μF to F (×10⁻⁶), mV to V (×10⁻³).
Key Fact: Show each step of working on a new line; examiners award marks for correct method even if arithmetic errors occur later.
Practice (10 minutes)
Q: explain the key ideas of circuit calculation questions
Answer:
Plenary (5 minutes)
Explain Back
Your student teaches the key points back to you without looking. Fill any gaps immediately.
Recall the key terms: key terms from circuit calculation questions. 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.
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 method for solving a circuit calculation question in an exam, using an example that involves finding the current through and power dissipated by a resistor. <div class="
The systematic method for solving circuit calculations has four steps. First, identify what is known and what is unknown: read the question carefully and list the given quantities with their values and units. Second, convert all values to base SI units: for example, 12 V stays as 12 V, but 10 kΩ becomes 10000 Ω and 5 mA becomes 0.005 A. Third, choose the correct formula and write it down before substituting. To find current, use I = V/R; to find power, use P = VI (or P = I²R if I and R are known). Fourth, substitute the values, calculate and state the answer with correct units. Example: A 12 V supply is connected across a 4 kΩ resistor. Current: I = V/R = 12/4000 = 0.003 A = 3 mA. Power: P = VI = 12 × 0.003 = 0.036 W = 36 mW. This method ensures method marks are earned even if a later arithmetic error occurs, because each step is clearly shown.
Exam Tips: Write the formula → substitute values → calculate answer → add units. This pattern secures method marks. | Always convert to base SI units before substituting: the most common error is mixing kΩ, mA or μF with formulas. | Label every quantity on your circuit diagram to make your working clear and easy to follow. | Check answers for sanity: if you calculate a current of 500 A through a small resistor, something is wrong. | In multi-step problems, state the result of each step clearly before moving to the next.
Common Errors: ✗ Substituting values with mixed units (e.g. V in volts but R in kΩ). ✓ Convert all values to base SI units first: 10 kΩ = 10000 Ω, 150 mA = 0.150 A, 47 μF = 47 × 10⁻⁶ F. ✗ Missing the ½ factor in capacitor energy calculations (using E = CV² instead of E = ½CV²). ✓ Always use E = ½CV² for capacitor energy and E = ½LI² for inductor energy; include the ½. ✗ Rearranging V = IR incorrectly (e.g. writing R = IV). ✓ R = V/I: divide voltage by current. Check by confirming the units: V/A = Ω. ✗ Forgetting to include units in the final answer. ✓ Every numerical answer must have the correct SI unit: V, A, Ω, W, J, F, H, s or Hz.
Stretch & Challenge (Grade 8-9):
Synoptic links: explain how circuit calculation questions connects to another Electronics topic you have studied
Real-world: research one real-world use or example of circuit calculation questions
Critical: "What are the limitations of the models used in circuit calculation questions?"
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
Consolidation: Re-answer any Lesson 3 practice questions answered incorrectly (20 mins)
Retrieval: Write flashcards for the key terms: key terms from circuit calculation questions (10 mins)
Exam practice: One past-paper question on circuit calculation questions from the board websites (15 mins)
Extension: Explain circuit calculation questions to someone else in your own words (10 mins)