The correct answer is: A. For inductive circuits.
Voltage-dependent resistors (VDRs), also known as varistors, are nonlinear resistors whose resistance decreases with increasing voltage. They are commonly used in inductive circuits to protect against overvoltages. When an overvoltage occurs, the VDR’s resistance decreases, which causes a current to flow through the VDR that dissipates the energy of the overvoltage.
Option B is incorrect because VDRs are not used to suppress surges. Surge suppressors are devices that are designed to protect electronic equipment from damage caused by power surges. Surge suppressors work by diverting the surge current to a ground wire.
Option C is incorrect because VDRs are not used as heating elements. Heating elements are devices that are designed to convert electrical energy into heat. Heating elements are commonly used in appliances such as toasters and ovens.
Option D is incorrect because VDRs are not used as current stabilizers. Current stabilizers are devices that are designed to maintain a constant current in a circuit. Current stabilizers are commonly used in power supplies.