Required Practical: Resistance of a Wire
This required practical covers Required Practical: Resistance of a Wire within Resistance & Ohm's Law for GCSE Physics. Revise Resistance & Ohm's Law in Electricity for GCSE Physics with 16 exam-style questions and 30 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 7 of 16 in this topic. Revise both the method and the reason for each step, because practical questions often test understanding rather than pure recall.
Topic position
Section 7 of 16
Practice
16 questions
Recall
30 flashcards
🧪 Required Practical: Resistance of a Wire
Equipment: Power supply, ammeter, voltmeter, metre ruler, resistance wire, crocodile clips
Method:
- Set up circuit with ammeter in series, voltmeter in parallel across wire
- Use crocodile clips at measured lengths (e.g., 10, 20, 30, 40, 50 cm)
- For each length: record V and I
- Calculate R = V / I for each length
- Turn off power between readings (prevent heating affecting results)
- Plot R (y-axis) against length (x-axis)
Expected result: Straight line through origin — R is directly proportional to length
Control variables: Same wire material, same cross-sectional area, constant temperature
Quick Check: A resistor has 12 V across it and 0.5 A flows through it. What is its resistance?
R = V / I = 12 ÷ 0.5 = 24 Ω.
Keep building this topic
Read this section alongside the surrounding pages in Resistance & Ohm's Law. That gives you the full topic sequence instead of a single isolated revision point.
Practice Questions for Resistance & Ohm's Law
Which of the following best describes electrical resistance?
Explain what is meant by an ohmic conductor.
Quick Recall Flashcards
16 questions on Resistance & Ohm's Law — practise free
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