Which of the following is NOT a source of electromagnetic interference (EMI)?

Copiers contain high-voltage charging elements, motors, and solenoids whose switching and mechanical operation generate significant broadband EMI.

Transformers generate alternating magnetic flux in their cores and windings, which radiates electromagnetic fields and makes them a well-known source of EMI.

Incandescent bulbs operate by passing current through a resistive tungsten filament, which produces heat and light without any switching transients, arc discharge, or varying magnetic flux that would radiate significant electromagnetic interference. Unlike fluorescent lights that use gas arc discharge and ballasts, or transformers and power cables that produce alternating magnetic and electric fields, incandescent bulbs behave as simple resistors with minimal electromagnetic emission across all frequencies.

Fluorescent lights use a gas arc discharge process and electronic or magnetic ballasts that produce substantial broadband electromagnetic interference.

Electrical power supply cables carrying alternating current radiate electromagnetic fields proportional to the current carried and can couple EMI to adjacent conductors.