Some electric guitars have a hollow or semi-hollow body with the resonating cavity found in an acoustic guitar, but the most popular electric guitars have solid bodies. The sound is produced by magnetic pickups and controlled by several knobs. If you pluck a string on an electric guitar that is not plugged in, the sound is barely audible. Without a soundboard and a hollow body, there is nothing to amplify the string's vibrations.

Most electric guitars are completely passive, they consume no power. However there are guitars with onboard electrics and batteries. The vibration of the strings are picked up by the bar magnet and sent to the amp.The amp's job is to take the guitar's signal and make it audible by boosting it enough to drive a speaker. The amp translates the electric signal into sound and creates the sound we know today from many guitar players of the last half-century.The fascinating thing about an electric guitar amp is that the amp is actually a part of the instrument.

 

 

Below are different sounds of the electric guitar (without amplification):

Clean (no effects) electric guitar.

Distorted (strong electric signal) electric guitar

Flangered (wavy sound) electric guitar