Question 155Electricity & Electronics - 1st Asst/Chief

The correct answer is D) varying the core's saturation. In a saturable-core reactor, the inductance of the load winding is controlled by changing the permeability of the core material. This is accomplished by varying the degree of magnetic saturation in the core. By adjusting the current in the control winding, the core can be driven into saturation, which reduces its permeability and, in turn, the inductance of the load winding. This principle allows for the regulation and control of the load circuit's voltage or current. The other options are incorrect because they do not accurately describe the mechanism by which a saturable-core reactor operates. Varying the core's inductance, dielectric strength, or reactance are not the primary means of control in this type of device.