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GCSE Physics equations practice

Select a relationship from the equation sheet, rearrange it and calculate with the right units.

Practise

Rearrange for current

A resistor has resistance 4.7 kΩ with potential difference 7.5 V. Calculate its current in A. Give your answer to 3 significant figures.

Equation: V = IR

Work through the calculation

Check intermediate steps, then use your unrounded working for the final answer. Each numerical check uses 3 significant figures. These steps provide support; the main answer is checked separately.

Step 1

Convert the stated resistance from kΩ to Ω. Give your answer to 3 significant figures.

Show this step

Multiply the kΩ value by 1000.

Answer: 4.70 × 10^3 Ω (3 significant figures).

Step 2

Now calculate the final answer to the main question.

Show this step

Rearrange V = IR to I = V / R. Convert kΩ to Ω.

Answer: 1.60 × 10^-3 A (3 significant figures).

Treat the given values as exact unless an uncertainty is stated.

Use decimals or e notation, e.g. 4.2e-3. Enter the unit separately.

Hint

Rearrange V = IR to I = V / R. Convert kΩ to Ω.

Worked solution
  1. R = 4.7 × 103 Ω.
  2. I = V / R = 7.5 / (4.7 × 103) A.
  3. Answer: 1.60 × 10-3 A (3 significant figures).
Another question
Question type: Mixed practice
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The question reference is attached automatically. Please leave out names and contact details.

Foundation and Higher: this set covers content common to both tiers. Some calculations need several steps.

Using the equation sheet

Use your board’s equation sheet alongside the question. Identify the quantities you have, choose the relationship and rearrange it before substituting. Convert prefixes and minutes first. Show your working on paper; the checker verifies the equation choice and final answer, not exam marks.

Equation sheets are supplied for the lifetime of the current GCSE specifications. Practise applying them and showing the calculation.

AQA equation sheets for current GCSE exams · OCR Gateway J249 equation sheet

GCSE scope

AQA 8463: 4.1.1.2, 4.1.1.4; 4.2.1.3–4; 4.3.1.1; 4.5.6.1.2, 4.5.6.2.2; MS 3b–c; OCR Gateway J249: P1.1; PM2.1i, PM2.2i; P3.2; P7.2; M3b–c. Tasks cover the selected skills listed above.

AQA specification · OCR Gateway specification

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