A3m deep, 4 m wide gate has water on one side with water surface at a height of 2.8m above its top edge. identify location of a pivot line with respect to the top of the gate in order to keep it vertical.

Which of the following components of a pid controlled accumulates the error over time and responds to system error after the error has been accumulated? a)- proportional b)- derivative c)- integral d)- on/off.