Variations of voltage or current over time are referred to as which of the following?

• A. Voltage
• B. Current
• C. Waveforms
• D. Signals

Answer: (A)

When voltage or current changes over time, the pattern it follows is called a waveform. A waveform describes the shape of that variation as time progresses—whether it’s a smooth sine wave, a sharp square wave, or a ramping triangle—capturing key characteristics like amplitude and frequency. This term is more precise than the others because it directly references how the quantity evolves over time, rather than the quantity’s instantaneous value at a single moment or a broader idea like information being carried. A signal is related, since many waveforms carry information, but the explicit term for the changing pattern itself is waveform.