Question:
In a PID controller, Derivative action responds to:
Options:
A) Instantaneous error
B) Accumulated error
C) Present error
D) Rate of error change
View Answer
Correct Answer: D) Rate of error change
Detailed Explanation
Derivative action is based on how fast the error is changing over time:
It does not depend on the magnitude of error alone. Instead, it reacts to the slope of the error signal.
- If error changes rapidly → Strong derivative output
- If error is constant → Derivative output becomes zero
- If error changes slowly → Small derivative effect
This predictive behavior helps reduce overshoot and improve damping.
Why Other Options Are Incorrect
A) Instantaneous error → That is Proportional action.
B) Accumulated error → That is Integral action.
C) Present error → Also describes Proportional action.