AMP - Aviation Maintenance Technician Powerplant Practice Exam

The magnetic circuit of a magneto consists of a permanent multi-pole rotating magnet with a core made of

1. hard steel

2. soft iron

3. electrical steel

4. cobalt alloy

The correct answer is: soft iron

The magnetic circuit of a magneto typically utilizes a rotating magnet, which is most often made of a permanent multi-pole material. This magnet creates a magnetic field that can be harnessed for energy production. However, in order to efficiently transfer this energy, the magnet must be paired with a core material that has high magnetic permeability. Hard steel, electrical steel, and cobalt alloy are all commonly used in the construction of cores, but they are not ideal for the magnetic circuit of a magneto. Hard steel, while strong and durable, has low permeability and would greatly reduce the efficiency of the magneto. Electrical steel and cobalt alloy are also not well-suited for use in a magneto because they are designed for use in electrical generators and motors, respectively. Soft iron, on the other hand, has high permeability and is therefore the most suitable material for the core of a magneto. It allows for efficient transfer of magnetic energy and thereby increases the performance of the magneto.