Topic 13 - Electromagnetic Induction Flashcards
1
Q
How do loudspeakers use electromagnetism
A
- An alternating current is sent through a coil of wire attached to the base of a paper cone.
- The coil surrounds one pole of a permanent magnet, and is surrounded by the other pole, so the current causes a force on the coil, due to the motor effect.
- This causes the cone to vibrate, resulting in variations in air pressure that forms a sound wave.
- The frequency of the sound waves is the same as the the frequency of the a.c.
