When a relay-logic Wired-AND gate is employed in a motor control circuit,
The relay-logic output, taken on the load side of the last set of series-connected NO relay contacts, is zero volts when any of the relay contacts are _____________.
A) none of the answers
B) activated
C) at-rest
D) either at-rest or activated
Answer:C
Share your understanding of this question with the correct explanation.
Explanation:
When a relay-logic Wired-AND gate is employed in a motor control circuit, the relay-logic output, taken on the load side of the last set of series-connected Normally Open (NO) relay contacts, is zero volts when any of the relay contacts are at-rest.
In a Wired-AND gate configuration, multiple relay contacts are connected in series. For the load to be energized and the output to have a voltage, all the series-connected relay contacts must be in their activated state (closed). If any of the relay contacts in the series chain are at-rest (open), the current flow is interrupted, and the output will have zero volts.
Here’s a breakdown of the options and why option C is the correct answer:
A) None of the answers: This option is not correct because there is a specific condition when the output is zero volts, as explained above.
B) Activated: When the relay contacts are activated (closed), the AND gate output will have a voltage (assuming other conditions in the control circuit are met). This option is incorrect because activated relay contacts do not cause the output to have zero volts.
C) At-rest: When any of the relay contacts in the series chain are at-rest (open), it breaks the continuity, and the AND gate output will have zero volts. This is the correct answer.
D) Either at-rest or activated: This option is not correct because the output being zero volts is only associated with the relay contacts being at-rest (open), not when they are activated (closed).