Correct Answer - Option 2 : Nickel and Iron alloys
Permalloy:
Permalloy is a Nickel-Iron magnetic alloy, with about 80% Nickel and 20% Iron content.
It is used as a magnetic core material in electrical and electronic equipment, and also in magnetic shielding to block magnetic fields.
Permalloy is used in transformer laminations and magnetic recording heads.
Magnetic properties:
- Low coercivity
- Near zero magnetostriction
- Very high magnetic permeability (It has a relative permeability of around 1,00,000)
- Significant anisotropic magnetoresistance.
Mu-metal:
Mu-metal is a Nickel-Iron soft ferromagnetic alloy with approximately 77% Nickel, 16% Iron, 5% Copper, and 2% Chromium or Molybdenum.
It is used for shielding sensitive electronic equipment against static or low-frequency magnetic fields.
Magnetic properties:
- Low coercivity so that it saturates at low magnetic fields.
- Very high magnetic permeability (Relative permeability is around 80,000 - 1,00,000)
- It has low hysteresis losses when used in AC magnetic circuits.
