FLORIDA BOARD OF PROFESSIONAL
ENGINEERS PRINCIPLES AND PRACTICE
CONTROL SYSTEMS EXAM WITH ACTUAL
QUESTIONS AND VERIFIED ANSWERS,
PLUS EXPLAINED RATIONALES/EXPERT
VERIFIED FOR GUARANTEED 100% PASS
2026/LATEST UPDATE/INSTANT
DOWNLOAD PDF
1. A pressure transmitter has a calibrated range of 0–100 psi and
produces a 4–20 mA output. What pressure corresponds to an
output current of 12 mA?
A. 25 psi
B. 40 psi
C. 50 psi
D. 75 psi
Answer: C. 50 psi
Rationale: The transmitter span is 16 mA, corresponding to a 100-psi
span. The current above the 4-mA zero is 12 − 4 = 8 mA. Therefore, the
fraction of span is 8/16 = 0.50. The corresponding pressure is 0.50 × 100
= 50 psi. This linear relationship is fundamental when scaling analog
instrumentation signals.
2. A temperature sensor has a first-order transfer function
G(s)=10s+11
What is its approximate time required to reach 95% of a step change?
1
,A. 1 s
B. 5 s
C. 10 s
D. 30 s
Answer: D. 30 s
Rationale: For a first-order system, the response is approximately 63.2%
complete after one time constant, 86.5% after two, 95% after
approximately three, and 98.2% after four. The time constant is 10 s, so
95% response occurs at approximately 3τ = 30 s. The time constant is an
important measure of sensor and process dynamic response.
3. A process has a transfer function
G(s)=2s+15
What is the steady-state process output for a unit step input?
A. 0.2
B. 1
C. 2
D. 5
Answer: D. 5
Rationale: For a stable system subjected to a unit step, the steady-state
output is determined by the DC gain, G(0). Setting s=0,
G(0)=15=5.
Therefore, the final output is 5. The numerator-to-denominator constant
ratio is the static gain of the process.
2
, 4. A feedback control system has a forward-loop transfer function
G(s)H(s). Which expression represents the closed-loop transfer
function for negative feedback?
A. G(s)+H(s)
B. G(s)H(s)
C. 1−G(s)H(s)G(s)
D. 1+G(s)H(s)G(s)
Answer: D. 1+G(s)H(s)G(s)
Rationale: For a standard negative-feedback system,
T(s)=1+G(s)H(s)G(s).
The denominator contains the characteristic equation 1+GH=0, which
determines the closed-loop poles and therefore strongly influences
system stability and dynamic behavior.
5. A proportional controller has a gain of 4. If the error signal is 3%,
what is the controller output change, assuming no integral or
derivative action?
A. 0.75%
B. 3%
C. 7%
D. 12%
Answer: D. 12%
Rationale: For proportional control,
u=Kpe.
With Kp=4 and e=3%,
u=4(3%)=12%.
3
, Increasing proportional gain makes the controller respond more strongly
to error, but excessive gain can produce oscillation or instability.
6. Which controller action is specifically capable of eliminating
steady-state offset caused by a constant disturbance in a typical
feedback loop?
A. Proportional
B. Integral
C. Derivative
D. Feedforward only
Answer: B. Integral
Rationale: Integral action continuously accumulates error over time. If a
nonzero steady-state error remains, the integral term continues changing
the controller output until the error is driven toward zero. Proportional
control alone generally leaves an offset when a persistent load
disturbance is present.
7. A PID controller is being tuned for a process with significant
measurement noise. Which controller action should generally be
treated cautiously because it amplifies high-frequency
measurement variations?
A. Integral
B. Proportional
C. Derivative
D. Bias
Answer: C. Derivative
Rationale: Differentiation emphasizes rapid changes. Measurement
noise often contains high-frequency components, and derivative action
4
ENGINEERS PRINCIPLES AND PRACTICE
CONTROL SYSTEMS EXAM WITH ACTUAL
QUESTIONS AND VERIFIED ANSWERS,
PLUS EXPLAINED RATIONALES/EXPERT
VERIFIED FOR GUARANTEED 100% PASS
2026/LATEST UPDATE/INSTANT
DOWNLOAD PDF
1. A pressure transmitter has a calibrated range of 0–100 psi and
produces a 4–20 mA output. What pressure corresponds to an
output current of 12 mA?
A. 25 psi
B. 40 psi
C. 50 psi
D. 75 psi
Answer: C. 50 psi
Rationale: The transmitter span is 16 mA, corresponding to a 100-psi
span. The current above the 4-mA zero is 12 − 4 = 8 mA. Therefore, the
fraction of span is 8/16 = 0.50. The corresponding pressure is 0.50 × 100
= 50 psi. This linear relationship is fundamental when scaling analog
instrumentation signals.
2. A temperature sensor has a first-order transfer function
G(s)=10s+11
What is its approximate time required to reach 95% of a step change?
1
,A. 1 s
B. 5 s
C. 10 s
D. 30 s
Answer: D. 30 s
Rationale: For a first-order system, the response is approximately 63.2%
complete after one time constant, 86.5% after two, 95% after
approximately three, and 98.2% after four. The time constant is 10 s, so
95% response occurs at approximately 3τ = 30 s. The time constant is an
important measure of sensor and process dynamic response.
3. A process has a transfer function
G(s)=2s+15
What is the steady-state process output for a unit step input?
A. 0.2
B. 1
C. 2
D. 5
Answer: D. 5
Rationale: For a stable system subjected to a unit step, the steady-state
output is determined by the DC gain, G(0). Setting s=0,
G(0)=15=5.
Therefore, the final output is 5. The numerator-to-denominator constant
ratio is the static gain of the process.
2
, 4. A feedback control system has a forward-loop transfer function
G(s)H(s). Which expression represents the closed-loop transfer
function for negative feedback?
A. G(s)+H(s)
B. G(s)H(s)
C. 1−G(s)H(s)G(s)
D. 1+G(s)H(s)G(s)
Answer: D. 1+G(s)H(s)G(s)
Rationale: For a standard negative-feedback system,
T(s)=1+G(s)H(s)G(s).
The denominator contains the characteristic equation 1+GH=0, which
determines the closed-loop poles and therefore strongly influences
system stability and dynamic behavior.
5. A proportional controller has a gain of 4. If the error signal is 3%,
what is the controller output change, assuming no integral or
derivative action?
A. 0.75%
B. 3%
C. 7%
D. 12%
Answer: D. 12%
Rationale: For proportional control,
u=Kpe.
With Kp=4 and e=3%,
u=4(3%)=12%.
3
, Increasing proportional gain makes the controller respond more strongly
to error, but excessive gain can produce oscillation or instability.
6. Which controller action is specifically capable of eliminating
steady-state offset caused by a constant disturbance in a typical
feedback loop?
A. Proportional
B. Integral
C. Derivative
D. Feedforward only
Answer: B. Integral
Rationale: Integral action continuously accumulates error over time. If a
nonzero steady-state error remains, the integral term continues changing
the controller output until the error is driven toward zero. Proportional
control alone generally leaves an offset when a persistent load
disturbance is present.
7. A PID controller is being tuned for a process with significant
measurement noise. Which controller action should generally be
treated cautiously because it amplifies high-frequency
measurement variations?
A. Integral
B. Proportional
C. Derivative
D. Bias
Answer: C. Derivative
Rationale: Differentiation emphasizes rapid changes. Measurement
noise often contains high-frequency components, and derivative action
4
