Speakers produce sound by translating an “electrical signal
into an audible sound”. Inside a speaker is an “electromagnet: a metal coil
which creates a magnetic field when an electric current flows through it”. The coil
acts very similarly to a regular magnet. It is able to reverse the “direction
of the current on the coil” which switches the “poles of the magnet”.
This electromagnet is “placed in front of a permanent
magnet” that has a fixed position. The “electromagnet is mobile” and able to
move. As electric currents are passed through the coil, the “direction of its
magnetic field is rapidly changed. This means that it is in turn attracted to
and repelled from the permanent magnet, vibrating back and forth.”
“The frequency of the vibrations governs the pitch of
the sound produced, and their amplitude affects the volume.”
Physics.org (n.d). Physics.org. Retrieved from http://www.physics.org/article-questions.asp?id=54.
No comments:
Post a Comment