What term denotes the time in electrical degrees by which one wave leads or lags another?

• A. Polarity
• B. Polyphase
• C. Phase difference
• D. Proton

Answer: (C)

Phase difference tells you how far one waveform is ahead or behind another in time, expressed in electrical degrees. For sinusoidal signals at the same frequency, a lead or lag corresponds directly to a phase angle: a lead of 90 degrees means the first wave reaches a given point in its cycle a quarter period earlier, while a lag of 60 degrees means it arrives that point later by that amount. This phase angle φ relates to the time shift by φ = ωΔt (or φ = 360°·Δt/T), linking the timing difference to a degree measure.

Polarity refers to the direction of the signal, not its timing; polyphase describes systems with multiple phases, not the lead/lag between two waves; proton is unrelated. So the term that best denotes the time in electrical degrees by which one wave leads or lags another is phase difference.