Physics 9702 · AS & A Level · Electromagnetic induction

Electromagnetic induction — practice question

(a)[2]

State Faraday’s law for electromagnetic induction.

(b)[3]

An alternating current is sent through a solenoid with an air core. An iron core is then placed inside the solenoid and kept fixed there. The current in the solenoid is now smaller. Explain why the root-mean-square (r.m.s.) value of the current in the solenoid is reduced as a result of inserting the core.

(c)[2]

Practical transformers are very efficient. Even so, some power is lost. State two sources of power loss within a transformer.

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