Magnetism and electromagnetismQuestion 199 of 1506

A magnetic core is 0.3 m long and carries 600 amp-turns of magnetomotive force. What is the field intensity?

  1. 600 amp-turns per metre
  2. 180 amp-turns per metre
  3. 2,000 amp-turns per metre
  4. 0.0005 amp-turns per metre
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Correct answer: 2,000 amp-turns per metre

Field intensity is the mmf spread over the length: 600 / 0.3 = 2,000 amp-turns per metre.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 14.4: Permeability and Saturation

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Questions last reviewed: 18 October 2026