Edexcel IGCSE Physics · Spec 6.8-6.9
Transformers: Using the Equations
Worked examples using the transformer equations.
Physics revision video
Transformers: Using the Equations
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Spec 6.8-6.9
What you need to know
- Use Vp over Vs equals Np over Ns
- Find a missing voltage or number of turns
- Use the power equation for an ideal transformer
Active recall
Quick check
Answer each question before opening the answer.
What is the transformer turns-and-voltage equation?
Vp ÷ Vs = np ÷ ns (primary/secondary voltage ratio equals the turns ratio).
For a 100% efficient transformer, what equation relates the power?
Vp × Ip = Vs × Is (power in = power out).
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