Which description matches the code following relay positions?

Which description matches the code following relay positions?

• A. Energized on its back, de-energized on its back, energized on its front, capable of coding
• B. De-energized on back, energized on back, energized on its front, capable of coding
• C. De-energized on its back, energized on its back, energized on its front, capable of coding
• D. Energized on its back, energized on its back, energized on its front, incapable of coding

Answer: (C)

The code after relay positions describes how the two contacts (back and front) behave in the two states of the relay coil: de-energized and energized, and it also notes whether the relay can provide a code. The correct description fits a coding relay where the back contact changes with energization, while the front contact remains energized in the described condition, and the device is capable of coding. Specifically, when de-energized, the back is de-energized; when energized, the back is energized; the front is energized in the described state, and the relay is capable of coding. This matches the expected behavior of a coding relay used to produce a code from relay positions. The other options conflict with how a coding relay operates—for example, implying energization in the de-energized state, or claiming the relay cannot code—so they don’t describe the correct behavior.

The code after relay positions describes how the two contacts (back and front) behave in the two states of the relay coil: de-energized and energized, and it also notes whether the relay can provide a code. The correct description fits a coding relay where the back contact changes with energization, while the front contact remains energized in the described condition, and the device is capable of coding. Specifically, when de-energized, the back is de-energized; when energized, the back is energized; the front is energized in the described state, and the relay is capable of coding. This matches the expected behavior of a coding relay used to produce a code from relay positions. The other options conflict with how a coding relay operates—for example, implying energization in the de-energized state, or claiming the relay cannot code—so they don’t describe the correct behavior.