Electric generators

• Recall that a changing magnetic field induces a potential difference. • Explain the operation of a moving coil microphone. • Recall that induced current generates a field opposing the original change. • Explain the output of an alternator (a.c. generation) using induction concepts. • Explain the adaptation of an alternator to a dynamo (d.c. generation). • Explain the principle of mutual induction in transformers. • Describe the relationship between potential difference ratio and turns ratio in transformers. • Apply transformer equations for potential difference, turns ratio, and power: $V_p \times I_p = V_s \times I_s$