Question

Steel is preferred to soft iron for making permanent magnets because,

• A. Susceptibility of steel is less than one
• B. Permeability of steel is slightly greater than soft iron
• C. Steel has more coercivity than soft iron
• D. Steel is more paramagnetic

Hint:

When choosing materials for permanent magnets, look for high coercivity and low susceptibility to ensure that the material retains its magnetization.

Answer 1

The Correct Option is C

The ability of a material to retain its magnetization after the external magnetic field is removed is called coercivity. For a permanent magnet, high coercivity is needed to retain its magnetization. 
- Steel has higher coercivity than soft iron, meaning it is more resistant to demagnetization. This is crucial for permanent magnets, which need to retain their magnetic properties over time. 
- Soft iron, on the other hand, has lower coercivity and is more easily magnetized and demagnetized, making it suitable for temporary magnets like electromagnets. 
Thus, steel is preferred over soft iron for making permanent magnets because it has more coercivity.