Which statement about shielding in cables is true?

• A. Shielding should be removed to improve flexibility.
• B. Shielding is purely cosmetic and offers no electrical benefit.
• C. Shielding reduces external interference when properly grounded.
• D. Shielding always adds excessive cost with no benefit.

Answer: (C)

Shielding in cables provides a barrier against electromagnetic interference. When the shield is properly grounded, it offers a low-impedance path for unwanted noise currents, so external fields are prevented from reaching the inner conductors and the cable’s signal stays cleaner. The shield also helps contain any radiation from the cable itself, reducing crosstalk and emissions. The effectiveness depends on a continuous shield and correct grounding; if the shield is ungrounded or poorly terminated, it can become a noise collector or even radiate more interference. This is why shielding reduces external interference when grounded, making it essential in noisy environments or long cable runs. Options claiming shielding should be removed for flexibility, that it’s merely cosmetic, or that it always adds cost with no benefit don’t reflect how shielding works in real electrical systems.