Question

Alnico can also be called magnetic steel.
(a)- True
(b)- False

Answer 1

Hint: Steel is an alloy of iron and Alnico is also an alloy of iron. Alnico was the strongest type of permanent magnet before the rare-earth magnets were developed. It is mainly composed of aluminium, nickel, and cobalt.

Complete step by step answer:
Alnico is a compound or substance that has very high magnetic properties.
The word Al-Ni-Co describes its composition and it is mainly composed of aluminium, nickel, and cobalt in addition to iron hence it is known as a family of iron alloys. Sometimes it includes copper and titanium. Alnico was the strongest type of permanent magnet before the rare-earth magnets were developed.
8-12% Al (aluminium), 15-26% Ni (nickel), 5-24% Co (cobalt), 6% Cu (copper), 1% Ti (titanium) and the remaining is balanced by iron is the main composition of Alnico. In 1931 its development started in Japan. They discovered that when the alloy of iron, nickel, and aluminium had coercivity of 400 oersteds which is more than that of the best magnet steels. So, it is considered as magnetic steel.
Alnico produces a strong magnetic field when it is magnetized thus making strong permanent magnets. When the alnico is heated it is red-hot but its magnetic properties are not lost and it is one of the compounds that have the highest Curie temperature. It has strong intermetallic bonding due to which it has a high melting point.

So the statement “Alnico can also be called magnetic steel” is true.

Note: In electric motors, electric guitar pickups, microphones, sensors, loudspeakers, magnetron tubes, and cow magnets alnico is widely used. Due to the discovery of rare-earth magnets, the use of alnico is suppressed.