Required Practical: Resistance of a Wire
Part of Resistance & Ohm's Law — GCSE Physics
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 14 exam-style questions and 30 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. 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
14 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.