Inductive proximity sensors generate which type of field to detect metal parts?

• A. Electric field
• B. Magnetic field
• C. Gravitational field
• D. Electrostatic field

Answer: (B)

Inductive proximity sensors generate a magnetic field. The coil inside produces an alternating magnetic field, and when a metal part comes near, it disturbs that field by inducing eddy currents in the metal. Those currents create a secondary magnetic field that changes the coil’s impedance, which the sensor detects and converts into a signal. This reliance on a magnetic field is what makes metals detectable without contact. Electric or electrostatic fields relate to capacitive sensing, which hinges on changes in capacitance with nearby objects, not the metal-focused mechanism of inductive sensing. Gravitational fields aren’t used for this type of proximity sensing.