WAEC - Physics (2021 - No. 39)
The following statements about a loudspeaker are correct except?
its contains a permanent magnet.
sound signal converted to varying current signal enters the speech coil.
the current in the speech coil creates a magnetic force on the coil.
the magnetic force on the speech coil is uni-directional.
Explication
The magnetic force on the voice coil is bi-directional, allowing it to move back and forth, producing sound waves.