Practice Question

1. Explain how a loudspeaker uses the motor effect.

When current flows through the coil in a magnetic field, a force is exerted on the coil due to the motor effect.

The direction of the force depends on the direction of the current (use Fleming’s left-hand rule).

2. Explain how a loudspeaker works

1. An alternating current passes through the coil of wire. 

2. This will set up a changing magnetic field around the coil which will interact with the permanent magnetic field of the magnet.

3.Due to the motor effect, the coil will experience a changing force. The force will change in direction constantly, due to the alternating current. 

4. As the coil moves backwards and forwards, it is attached to the cone, so the cone vibrates backwards and forwards creating sound waves 

3. If the frequency of current is increased, how would this affect the sound produced.

Sound wave produced would have a higher frequency, which means the sound produced would be of a higher pitch