Question

Which condition should the variable potential difference (which feeds a loudspeaker) satisfy to emit an audible sound?

A. The potential difference must be constant.
B. The potential difference must be zero.
C. The potential difference must be an alternating current (AC).
D. The potential difference must be a direct current (DC).

Answer 1

The potential difference meant to feed a loudspeaker must be an alternating current (AC) to emit an audible sound, as AC enables the loudspeaker to produce sound waves corresponding to the fluctuating electrical signal.

Step-by-step explanation:

To emit an audible sound, the variable potential difference which feeds a loudspeaker should satisfy the condition of being an alternating current (AC). This is because sound waves are oscillations of air pressure that can be represented electronically as an AC signal. For a loudspeaker to convert electrical signals into sound waves, the potential difference must fluctuate, which is characteristic of an AC, not a constant or direct current (DC).