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Magnetism and electromagnetism

Magnetism and electromagnetism

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Question 28

An AC mains power adapter for a gaming device contains a step-down transformer.

a.

The number of turns on the primary coil of a step-down transformer is:

  • A the same as the number of secondary turns
  • B more than the number of secondary turns
  • C less than the number of secondary turns
  • D zero
[1]
b.

This transformer is designed to reduce the voltage from 240 V to 9 V.

The primary current is 0.15 A.

State the equation linking primary voltage, primary current, secondary voltage, and secondary current for a transformer.

[1]
c.

Calculate the secondary current, assuming that the transformer is 100% efficient.

[2]
d.

A user notices that the power adapter becomes warm when it is working. Suggest how this will affect the power output of the transformer compared to its power input.

[2]
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Magnetism and electromagnetism Questions

  1. IGCSE
  2. /Physics
  3. /Magnetism and electromagnetism

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