Which statement best describes the purpose of a shield around a signal lead?

Which statement best describes the purpose of a shield around a signal lead?

• A. It protects against noise.
• B. It reduces resistance.
• C. It increases current.
• D. It changes phase angle.

Answer: (A)

Shielding a signal lead is meant to protect the signal from electrical noise and interference. The conductive shield surrounds the conductor and is usually tied to ground, so noise that’s picked up on the outside is diverted away from the signal path. This preserves signal quality, especially in environments with EMI or RFI. It doesn’t aim to reduce resistance or to increase current, and shielding doesn’t inherently change the signal’s phase angle. The primary purpose is to prevent noise from corrupting the signal, making the statement about protecting against noise the best description.

Shielding a signal lead is meant to protect the signal from electrical noise and interference. The conductive shield surrounds the conductor and is usually tied to ground, so noise that’s picked up on the outside is diverted away from the signal path. This preserves signal quality, especially in environments with EMI or RFI.

It doesn’t aim to reduce resistance or to increase current, and shielding doesn’t inherently change the signal’s phase angle. The primary purpose is to prevent noise from corrupting the signal, making the statement about protecting against noise the best description.