Red Seal Electrician Practice
Magnetism and electromagnetismQuestion 380 of 1506

Why does a soft iron core release a load when coil current stops?

  1. The coil short-circuits when the current stops
  2. The core heats up and melts away
  3. The coil reverses its polarity by itself
  4. Soft iron has low retention, so the field collapses
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Correct answer: Soft iron has low retention, so the field collapses

Soft iron does not hold magnetism, which is useful for relays and lifting magnets.

Source: Electrical Fundamentals Competency (Industry Training Authority of BC), 3.2: Electricity and Magnetism

Practice magnetism and electromagnetism

Questions last reviewed: 18 October 2026