---
title: "Properties and uses of soft magnetic materials"
subject: "Electrical Engineering Material"
chapter: 4
key: "semester_3/electrical_engineering_material:soft-magnetic-properties-uses"
source: https://www.bctengineer.com/q/semester_3/electrical_engineering_material/soft-magnetic-properties-uses
site: BCT Engineering
---

# Properties and uses of soft magnetic materials

Electrical Engineering Material · Chapter 4: Magnetic Materials

- Asked in: 2069 Asar, 2+2 marks
- Video: [#4 TRANSFORMER MAGNETIC MATERIAL \CRGO\ soft and hard magnetic materail](https://www.youtube.com/watch?v=A3RyArhpl3o) — EleKtriSk GURU
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/electrical_engineering_material/soft-magnetic-properties-uses
- Whole chapter: https://www.bctengineer.com/md/semester_3/electrical_engineering_material/chapter-4

## Question

What are the properties of soft magnetic materials and give the examples of the uses of soft magnetic materials.

## Short answer

Soft magnetic materials have low coercivity, high permeability, narrow hysteresis loop, low loss, and high resistivity. Uses include transformer cores (Si-steel), relay cores, high-frequency transformers and inductors (soft ferrites), and magnetic shielding (permalloy).

## Answer

**Soft magnetic materials** are those that can be magnetized and demagnetized easily.

#### Properties
- **Low coercivity** ($H_c$ < about 1000 A/m) and low retentivity.
- **High permeability** ($\mu_r$ of thousands to $10^5$).
- **Narrow, tall hysteresis loop**, so **low hysteresis loss**.
- **High saturation flux density**.
- High resistivity (in Si-steel and ferrites) for **low eddy-current loss**.
- Few impurities and defects, so domain walls move easily.

```text
      B
      ^  __
      | / /   narrow loop
  ----+/-/----> H
     /-/ |
```

#### Uses
| Material | Use |
|---|---|
| Silicon steel (laminated, CRGO) | Cores of transformers, motors, generators |
| Soft iron | Relay cores and armatures, electromagnets, lifting magnets |
| Permalloy, Mumetal | Magnetic shielding, sensitive relays, recording heads, CTs |
| Soft ferrites (MnZn, NiZn) | High-frequency transformers, SMPS, inductors, antenna rods |
| Amorphous alloys | Low-loss distribution transformers |

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Soft magnetic materials are those that:
   A. Can be magnetized and demagnetized easily
   B. Retain magnetism for life
   C. Are not affected by fields
   D. Have wide loops
   Answer: A. They have low coercivity and low retentivity. (Key point: Definition)

2. Which set describes soft magnetic materials?
   A. High coercivity, low permeability
   B. Low coercivity, high permeability, narrow loop, low hysteresis loss
   C. Wide loop, high loss
   D. Low permeability, high retentivity
   Answer: B. Domain walls move easily. (Key point: Properties)

3. Silicon steel (CRGO) is used for:
   A. Permanent magnets
   B. Magnetic tapes
   C. Cores of transformers, motors and generators
   D. Superconductors
   Answer: C. Its low loss suits alternating flux. (Key point: Silicon steel)

4. Soft ferrites suit high-frequency use because of:
   A. High hysteresis loss
   B. Very high Hc
   C. High conductivity
   D. High resistivity giving low eddy-current loss
   Answer: D. Ceramic ferrites are poor conductors. (Key point: Ferrites)

## Related in Electrical Engineering Material

- [Applications of soft magnetic materials](https://www.bctengineer.com/question.md?key=semester_3%2Felectrical_engineering_material%3Asoft-magnetic-applications) — Electrical Engineering Material, chapter 4, asked 2×
- [Hard vs soft magnetic materials for relays](https://www.bctengineer.com/question.md?key=semester_3%2Felectrical_engineering_material%3Ahard-soft-relay) — Electrical Engineering Material, chapter 4
- [Hard vs soft magnetic materials by hysteresis](https://www.bctengineer.com/question.md?key=semester_3%2Felectrical_engineering_material%3Ahard-soft-hysteresis) — Electrical Engineering Material, chapter 4
- [Hard magnets and soft high-frequency materials](https://www.bctengineer.com/question.md?key=semester_3%2Felectrical_engineering_material%3Ahard-permanent-soft-high-frequency) — Electrical Engineering Material, chapter 4
- [Classification of magnetic materials by magnetization](https://www.bctengineer.com/question.md?key=semester_3%2Felectrical_engineering_material%3Aclassify-magnetic-materials) — Electrical Engineering Material, chapter 4, asked 6×
- [Magnetic moments; ferro vs ferrimagnetic materials](https://www.bctengineer.com/question.md?key=semester_3%2Felectrical_engineering_material%3Adipole-moment-ferro-ferri) — Electrical Engineering Material, chapter 4

## Related in other subjects

- [Soft versus hard magnetic materials](https://www.bctengineer.com/question.md?key=semester_5%2Felectric_machine_design%3Asoft-hard-magnetic-materials) — Electric Machine Design, chapter 1, asked 5×
- [Soft magnetic materials and commercial applications](https://www.bctengineer.com/question.md?key=semester_5%2Felectric_machine_design%3Asoft-magnetic-applications) — Electric Machine Design, chapter 1, asked 2×
- [Hysteresis loop energy, hard and soft magnetic materials](https://www.bctengineer.com/question.md?key=semester_4%2Felectrical_machines_i%3Ahysteresis-area-energy-hard-soft) — Electrical Machines I, chapter 1
- [Soft magnetic material, Faraday's laws](https://www.bctengineer.com/question.md?key=semester_4%2Felectrical_machines%3Asoft-magnetic-faraday-laws) — Electrical Machines, chapter 1