AME 11 Q2

Correct Answer: B) The float drops, causing the control valve to close, reducing the inflow.
Explanation: In a float and lever proportional system, increasing the flow out of the tank causes the water level to decrease. As a result, the float drops, which signals the control mechanism to close the inflow valve, thereby reducing the inflow to balance the system and maintain the desired water level.

Correct Answer: A) Increase the gain by reducing the proportional band; decrease the gain by increasing the proportional band.
Explanation: In control systems, gain is inversely related to the proportional band. By reducing the proportional band, the system responds more aggressively, increasing the gain. Conversely, increasing the proportional band reduces the system's response, decreasing the gain.

Correct Answer: B) The steady-state tank level will oscillate more and be less stable.
Explanation: Increasing the controller gain in a float and lever proportional system makes the control system more responsive to deviations from the setpoint. When the outflow is increased, a higher gain causes the system to react more aggressively, which can lead to increased oscillations and instability around the steady-state tank level.

Correct Answer: B) Proportional band is inversely proportional to gain.
Explanation: In a control system, the proportional band is the range of input values over which the output is proportional. The gain is the reciprocal of the proportional band, meaning as the proportional band decreases, the gain increases, and vice versa.

Correct Answer: A) The float rises with the water level, causing the lever to close a valve, stopping the inflow of water when the desired level is reached.
Explanation: In a float and lever proportional system, the float moves up as the water level rises, causing the lever to gradually close the valve, reducing the inflow of water and maintaining the water level within a desired range.

Correct Answer: B) Integral action increases the control output to eliminate steady-state error over time by integrating the error signal.
Explanation: Integral action in a control system accumulates the error over time and adjusts the control output to eliminate steady-state error. This action is based on the integral of the error signal, meaning it considers the total accumulated error to bring the process variable closer to the setpoint.