Rankers Physics

Magnetic Properties of Matter: Practice Problem & Solution

29. Electromagnets are made of soft iron because soft iron has: (2010 Pre)
High retentivity and low coercive force
Low retentivity and high coercive force
High retentivity and high coercive force
Low retentivity and low coercive force

Solution Explained:

To solve this problem, we apply the core principles of Magnetic Properties of Matter. Understanding the underlying formula is key to arriving at the correct answer below:

An electromagnet should easily magnetize when current is switched on and readily lose its magnetism when current is turned off. Thus, the material must have low retentivity and low coercivity.

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