Which statement describes a three-phase power source?

Question

Options

• ATwo voltage sine wave references consisting of two "hot" wires and a ground
• BOne voltage sine wave reference consisting of a "hot" wire, a neutral wire, and a ground
• CThree voltage sine wave references consisting of one "hot" wire, one neutral wire, and a ground
• DThree voltage sine wave references consisting of three "hot" wires and accompanying neutral and a ground

• A
  5% (3)
• B
  10% (6)
• C
  2% (1)
• D
  84% (51)

Explanation

Option D correctly identifies that a three-phase power source produces three separate voltage sine wave references, each offset from the others by 120 degrees, and each carried on its own dedicated "hot" wire, with a shared neutral and ground completing the system. Option A describes a two-phase or split-phase configuration, not three-phase. Option B describes standard single-phase power, like a typical household 120V outlet, which has only one hot wire and one sine wave reference. Option C is a tempting trap because it correctly names three sine wave references but incorrectly assigns them to only one hot wire - in reality, each sine wave reference requires its own dedicated hot conductor. A reliable memory anchor: match the number of phases to the number of hot wires, so three-phase always means three hots.

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