Question

Why is the loudness of sound heard by a plucked wire increased when mounted on a sound board?

Answer 1

A wire mounted on a soundboard is plucked, the surface area of vibrating air increases and sends forth a greater amount of energy, So the amplitude of vibration is large and louder is the sound

Answer 2

The loudness of sound increases when a plucked wire is mounted on a soundboard because the soundboard has a larger surface area. It vibrates along with the wire, amplifies the sound through resonance, and pushes more air particles, producing a louder sound. This is why soundboards are used in instruments like guitars and pianos.