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Which magnetic properties should the core material possess to be suitable for an electromagnet?

1. High retentivity and low coercivity
2. Low retentivity and low coercivity
3. High retentivity and high coercivity
4. Low retentivity and high coercivity

Correct answer: Low retentivity and low coercivity

Solution

An electromagnet must lose magnetism when current stops (low retentivity) and be easily demagnetized (low coercivity). Soft iron has both, so the answer is low retentivity and low coercivity.

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