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Answer

Explain how an electric motor works

1 Direct current passes through coil 2 Magnetic field forms around wire 3 Interacts with permanent field creates force on wire 4 Current opposite each side forces opposite turning moment 5 Split ring commutator reverses current every half turn keeps rotation going

What is the purpose of a split ring commutator

Reverses direction of current every half turn reverses force direction keeps coil rotating same way

Explain how a loudspeaker works

1 Alternating current flows through coil 2 Coil in permanent magnetic field experiences force motor effect 3 Current direction changes force direction changes 4 Coil vibrates same frequency as AC 5 Attached cone vibrates 6 Cone moves air molecules creates sound waves

Explain the generator effect why ammeter reading occurs

1 Magnetic field exists around magnet 2 Moving magnet/coil causes field lines to cut through coil 3 Potential difference induced across coil 4 If circuit complete induced current flows

How to increase induced potential difference or current

Move magnet or coil faster use stronger magnetic field more turns on coil

What happens if magnet stops moving

No field lines cut no pd or current induced

What happens if magnet direction reversed

Induced current flows opposite direction

Explain how an AC generator alternator works

1 Coil rotated in magnetic field 2 Coil cuts field lines induces pd 3 Slip rings maintain continuous connection 4 Output is alternating current direction changes every half turn

Explain how a DC generator dynamo works

1 Coil rotated cuts field lines induces pd 2 Split ring commutator reverses connection every half turn 3 Output remains same direction direct current

How to increase generator output pd

Rotate coil faster stronger magnetic field more turns of coil larger coil area

Explain how a microphone works generator effect

1 Sound waves hit diaphragm make it vibrate 2 Diaphragm moves coil attached to it 3 Coil moves inside permanent magnetic field 4 Induces alternating pd across coil 5 Pd converted to electrical signal sent to amplifier

Explain how a transformer works

1 Alternating pd across primary coil 2 Creates constantly changing magnetic field in iron core 3 Changing field cuts through secondary coil 4 Induces alternating pd across secondary coil 5 Works only with AC not DC

How to increase output pd from transformer

More turns on secondary coil or fewer turns on primary