When there is only one phase, phase duration equals the

• A. Amplitude
• B. Pulse duration
• C. Interpulse interval
• D. Number of phases

Answer: (B)

The concept is that when a pulse has only one direction of current flow, the time the current lasts is the same whether you call it a phase or a pulse. Phase duration is the length of time a single direction of current flows; if there’s only one phase in the pulse, that duration is the total pulse duration. Amplitude is about how strong the current is, not how long it lasts; the interpulse interval is the pause between separate pulses, and the number of phases refers to how many directional components are present, not the duration. If there were multiple phases, the pulse duration would encompass all those phases (and any gaps) rather than matching a single phase duration.