Which statement about biased relays is correct?

Which statement about biased relays is correct?

• A. Relays that switch in both directions.
• B. Relays that operate with alternating current only.
• C. Relays that ignore polarity and respond to voltage magnitude.
• D. Relays that observe polarity in one direction.

Answer: (D)

Biased relays are designed to be polarity-sensitive, meaning they respond to voltage or current in one preferred direction due to an internal bias. That directional sensitivity is what lets the relay energize or operate when the applied polarity matches the bias, and behave differently when the polarity reverses. So the statement that they observe polarity in one direction best describes their function. They’re not simply bidirectional switches, nor are they defined by operating only on AC or by ignoring polarity—the hallmark is that the response depends on the direction of the applied polarity.

Biased relays are designed to be polarity-sensitive, meaning they respond to voltage or current in one preferred direction due to an internal bias. That directional sensitivity is what lets the relay energize or operate when the applied polarity matches the bias, and behave differently when the polarity reverses. So the statement that they observe polarity in one direction best describes their function. They’re not simply bidirectional switches, nor are they defined by operating only on AC or by ignoring polarity—the hallmark is that the response depends on the direction of the applied polarity.