Meters and troubleshootingQuestion 1186 of 1506

Two sine waves of the same frequency and equal amplitude give a circle on a scope in X-Y mode. What is the phase shift?

0 degrees
45 degrees
180 degrees
90 degrees

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Correct answer: 90 degrees

The figure is a perfect circle when the shift is exactly 90 degrees and the amplitudes are equal.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 12.2: Frequency and Phase Measurement

Questions last reviewed: 18 October 2026

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