In shielded cables, shields are typically connected to which potential?

In shielded cables, shields are typically connected to which potential?

• A. Ground or reference potential
• B. Live
• C. Data signal line
• D. None

Answer: (A)

Shielding in cables works by giving any external interference a low-impedance path to flow away from the inner conductors, keeping the signal clean. To do this effectively, the shield is tied to a stable reference potential, typically ground, so it stays at a defined potential and can shunt noise to earth rather than into the signal path. Grounding also helps prevent the shield from floating, which could create unwanted voltage differences and more interference. Choosing to connect the shield to live would force it to follow a hazardous potential and undermine shielding, while tying it to a data signal line would couple noise into or out of the actual signal. Therefore, connecting the shield to ground or a reference potential is the best practice.

Shielding in cables works by giving any external interference a low-impedance path to flow away from the inner conductors, keeping the signal clean. To do this effectively, the shield is tied to a stable reference potential, typically ground, so it stays at a defined potential and can shunt noise to earth rather than into the signal path. Grounding also helps prevent the shield from floating, which could create unwanted voltage differences and more interference.

Choosing to connect the shield to live would force it to follow a hazardous potential and undermine shielding, while tying it to a data signal line would couple noise into or out of the actual signal. Therefore, connecting the shield to ground or a reference potential is the best practice.