Free worksheet and solutions · AQA GCSE · 8463
AQA GCSE Physics Transformers Turns Ratio and Efficiency Worksheet
AQA GCSE Separate Physics Higher transformer worksheet with answers. Use turns ratios, power and efficiency to assess a realistic transmission system.
What is covered
Questions and skills covered
The worksheet contains 6 pages of printable questions. A separate 6-page solutions PDF makes it easy to mark, review or share answers after the activity.
- Iron and easy magnetisation
- Changing magnetic field induces secondary p.d.
- Electrically separate coils; secondary current needs a completed circuit
- Steady d.c. versus a.c., excluding switching transients
- Step-down identification and voltage/turn-number rearrangements
- Inverse current change at fixed ideal output power
- Multistep turns ratio to voltage, power and current
- Real input/output power and decimal/percentage efficiency
- Rate of unwanted energy transfer in watts
- More efficient unit can fail required output at recorded operating point
- Measured versus ideal current-limit decision
- Efficiency rearrangement for required input power
- Higher transmission p.d., lower current and lower cable heating loss
About this activity
A solar-powered field laboratory selects transformer windings and checks which supply meets a required instrument power without exceeding a current limit.
Before you start
After teaching transformer action and the turns ratio, P=VI, efficiency and transmission losses. Equations supplied; no A-level induction mathematics.
A question from the worksheet
Question5(d), pupil page6
A transformer delivers60 W at96% efficiency from48 V. Does it meet a1.40 A input-current limit?
Show the answer
Input power60/0.96=62.5 W; current62.5/48=1.302 A, below1.40 A. It meets this stated criterion.
Common error: Treating every transformer as100% efficient or using the voltage ratio as a same-direction current ratio.
Revise the physics
Specification fit
AQA GCSE Physics Worksheets
8463 · 4.7.3.4, 4.2.4.3, 4.2.4.1, 4.1.2.2
- 8463: 4.7.3.4, 4.2.4.3, 4.2.4.1, 4.1.2.2
Choose the correct pathway: Whole worksheet: Separate Physics 8463 Higher only. No Foundation or Combined Trilogy route. Shared supporting power/efficiency ideas do not change this eligibility.
Classroom use
Use the worksheet for class practice, homework, intervention, cover work or revision. Keep the PhysicsUK attribution intact when sharing copies with pupils.