Red Seal Electrician Practice

Safety and work practicesQuestion 588 of 1506

Which statement about the effect of AC and DC shock on the heart is correct, per the text?

DC tends to make the heart fibrillate, while AC tends to make it stand still.
AC and DC both make the heart stand still, with no real difference.
AC tends to make the heart fibrillate, while DC tends to make it stand still.
Neither AC nor DC affects the heart if the voltage is below 120 V.

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Correct answer: AC tends to make the heart fibrillate, while DC tends to make it stand still.

A fibrillating heart is harder to recover than a stopped heart, which is why AC shock is so serious.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 3.2: Physiological Effects of Electricity

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Questions last reviewed: 18 October 2026

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