A signal cable runs close to unshielded mains wiring carrying rms at
PHYSICS · Multi-part · Fermi University Physics · Electronics, Instrumentation & Communication · Circuit foundations and passive networks · Circuit foundations and passive networks
Electronics for Measurement, Ch The bench: probes, cables, grounds and what the instrument shows
Problem
A signal cable runs close to unshielded mains wiring carrying 230V rms at 50Hz, and an estimated stray capacitance of 2.0pF couples the mains conductor to the signal line.
((a)) Estimate the rms current this coupling injects into the signal line.
((b)) Estimate the pickup voltage this current produces at a node whose Thevenin resistance to ground is 1.0kΩ, and at a node whose Thevenin resistance is 100kΩ.