AME 11 End of Unit – SVE Study

AME 11 End of Unit Quiz

1 / 12

State the reasons for fitting a pneumatic process valve with a feedback positioner.

C) A feedback positioner is fitted to reduce the overall power consumption of the valve actuator, improving energy efficiency.

B) A feedback positioner is fitted to increase the air pressure supplied to the actuator, which helps in enhancing the overall force applied to the valve.

D) A feedback positioner is fitted to provide a backup control signal in case the primary control system fails, ensuring the valve remains operational.

A) A feedback positioner is fitted to monitor the valve position and provide real-time correction signals to ensure the valve remains at the desired position, improving accuracy and stability in the process control.

2 / 12

Describe a possible effect of excessive Integral Action.

D) Excessive Integral Action can increase the system’s ability to predict future errors accurately, leading to improved overall system stability.

B) Excessive Integral Action can cause the system to oscillate or exhibit sustained oscillations around the setpoint due to an overcompensation of errors.

A) Excessive Integral Action can lead to a quick and accurate response to setpoint changes, reducing the time required to reach the target value.

C) Excessive Integral Action can make the control system unresponsive to errors, resulting in a steady and stable system performance.

3 / 12

Explain the purpose of Integral Action.

D) Integral action maintains a constant output level regardless of the error to keep the system stable.

B) Integral action integrates the error over time to eliminate steady-state error, ensuring that the system eventually reaches the setpoint.

A) Integral action adjusts the control output based on the magnitude of the error, aiming to quickly correct deviations from the setpoint.

C) Integral action predicts future errors by adjusting the control output based on the rate of change of the error.

4 / 12

What is the primary characteristic of a Discontinuous (On-Off) control system?

D) The system provides proportional control based on the error magnitude.

C) The system adjusts output in small increments.

B) The output is either fully on or fully off, with no intermediate states.

A) The output is continuously variable.

5 / 12

What happens when the flow out is increased in a system where the water tank level is controlled by a float and lever proportional system?

D) The float drops, causing the control valve to open more to increase the inflow.

A) The float rises, causing the control valve to open more to increase the inflow.

C) The float rises, causing the control valve to close, reducing the inflow.

B) The float drops, causing the control valve to close, reducing the inflow.

6 / 12

Describe the effect of excessive Derivative Action.

B) Excessive Derivative Action can cause the system to become overly sensitive to noise, leading to oscillations and instability.

D) Excessive Derivative Action can decrease the system’s overall response time and improve its accuracy in maintaining the setpoint.

A) Excessive Derivative Action can lead to a sluggish response time and an increase in steady-state errors.

C) Excessive Derivative Action can result in a system that quickly reaches the setpoint without overshooting or oscillating.

7 / 12

Explain proportional bandwidth in control terms.

D) Proportional bandwidth is the extent of variation in the system output for a given change in proportional gain. Reason: This describes the effect of changing proportional gain on output variation, rather than the range of input values affecting proportional control.

A) Proportional bandwidth refers to the range of input values over which the proportional control action is effective in adjusting the output of a system. Reason: This describes how the range within which proportional control can operate effectively is defined, focusing on the input values that impact the output.

C) Proportional bandwidth refers to the frequency range over which the proportional controller can maintain a constant output. Reason: This describes frequency response rather than the range of input values within which proportional control is effective.

B) Proportional bandwidth is the measure of how quickly a system can respond to changes in the proportional gain setting. Reason: This describes response time rather than the range of input values for proportional action.

8 / 12

How can the gain of a control system be increased or decreased?

C) Increase the gain by adding derivative control; decrease the gain by removing derivative control.

B) Increase the gain by increasing the integral time; decrease the gain by reducing the integral time.

A) Increase the gain by reducing the proportional band; decrease the gain by increasing the proportional band.

D) Increase the gain by reducing the setpoint; decrease the gain by increasing the setpoint.

9 / 12

With reference to engine governors, explain speed droop.

A) Speed droop is the reduction in engine speed that occurs when the engine is subjected to an increase in load, relative to the no-load speed. Reason: Speed droop measures how much the engine speed decreases from its no-load speed when a load is applied.

D) Speed droop describes the governor's ability to maintain a constant engine speed despite fluctuations in ambient temperature. Reason: Speed droop is related to load changes, not temperature fluctuations.

C) Speed droop is the amount by which the governor’s set point changes to match variations in fuel quality. Reason: Speed droop pertains to load variations, not fuel quality.

B) Speed droop refers to the increase in engine speed when the governor's sensitivity is reduced. Reason: Reducing sensitivity affects response time, not speed droop.

10 / 12

Explain dead zone in control terms.

D) Dead zone is the ability of a control system to maintain output stability despite fluctuations in the input. Reason: This describes system stability rather than dead zone, which is specifically about input-output response range.

B) Dead zone is the time required for a system to stabilize after a disturbance. Reason: This describes settling time rather than dead zone, which is about the unresponsive range in the input-output relationship.

A) Dead zone refers to a range within which changes in input do not produce any change in the output of a control system. Reason: This correctly describes dead zone as a region where the system is unresponsive to inputs within that range.

C) Dead zone is the amount of time it takes for the control system to start responding after a command is issued. Reason: This describes the delay or lag in response, not the concept of dead zone.

11 / 12

How does hysteresis improve the performance of an On-Off control system?

C) It allows the system to adjust output continuously.

B) It prevents rapid cycling by creating a dead zone between switching on and off.

D) It enables the system to predict and correct future errors.

A) It increases the switching frequency of the system.

12 / 12

2. Which of the following is a typical application of an On-Off control system?

D) Flow control in a proportional valve system.

A) Speed control of a variable frequency drive.

B) Temperature control in a household thermostat.

C) Pressure regulation in a hydraulic system.

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