Magnetorquer is one of the practical actuators which generates magnetic Torques and changes the total momentum of the satellite. Its used to control the attitude of satellite beside other actuators like reaction wheel or thruster.
The type of alloys used to make these actuators is very crucial. In other words, the high magnetic permeability coefficient of the nucleus and the low magnetic residue in the nucleus are very important.
The linearity of the magnetic field generated by this actuator as well as the current and time characteristics when the core is saturated are very important parameters in this actuator.