A laptop battery charger contains a step-down transformer.
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This transformer is designed to reduce the voltage from 230 V to 12 V.
The primary current is 0.25 A.
(i) State the equation linking primary voltage, primary current, secondary voltage and secondary current for a transformer.
[1]
(ii) Calculate the secondary current, assuming that the transformer is 100% efficient.
secondary current = ............................................... A [2]
A student notices that the charger becomes warm when it is working.
Suggest how this will affect the output of the transformer.
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