<span>An increase in voltage causes the flow of electric current to increase.
Voltage and flow of electric current are <em>directly related</em>, so when the voltage increases, the flow of electric current increases, as well. If the voltage were to decrease, the flow of electric current would decrease, too. </span>
supply it with more energy. one way to do is to produce vibrations in the same frequency as the wave. This would cause resonance leading to higher amplitude