Free Control Systems MCQs with Answers
72 Control Systems MCQs from Electrical Engineering, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
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- A. head
- B. liquid flow
- C. liquid flow rate
- D. none of the above
Explanation: Liquid head is the potential that drives liquid flow, so it corresponds to electrical voltage.
Correct answer: head- A. charge
- B. resistance
- C. reciprocal of inductance
- D. reciprocal of conductance
- E. none of the above
Explanation: The viscous-friction term is proportional to velocity, just as resistance is proportional to current in the voltage analogy.
Correct answer: resistance- A. charge
- B. current
- C. inductance
- D. resistance
Explanation: Mechanical mass opposes changes in velocity, while inductance opposes changes in current.
Correct answer: inductance- A. momentum
- B. velocity
- C. displacement
- D. mass
Explanation: In the force-current analogy, force corresponds to current and velocity corresponds to voltage.
Correct answer: mass- A. Error detector
- B. Final control element
- C. Sensor
- D. Oscillator
Explanation: An automatic control system commonly uses an error detector, sensor, and final control element to measure and correct the output.
Correct answer: Oscillator46. Due to which of the following reasons excessive bond width in control systems should be avoided ?
- A. It leads to slow speed of response
- B. It leads to low relative stability
- C. Noise is proportional to band width
- D. None of the above
Explanation: A wider bandwidth allows more noise, because the total noise power generally increases with the frequency range passed by the system.
Correct answer: Noise is proportional to band width- A. final control element
- B. amplifier
- C. comparator
- D. sensor
- E. none of the above
Explanation: The controller processes the error signal and sends its corrective command to the final control element, such as a valve, motor, or…
Correct answer: final control element- A. Underdamping
- B. Overdamping
- C. Poor stability at reduced values of open loop gain
- D. Low-level oscillations
Explanation: Backlash introduces a dead zone and can produce small sustained oscillations or limit cycles even when the linear control system is…
Correct answer: Low-level oscillations- A. sensor
- B. clipper
- C. comparator
- D. amplifier
Explanation: A controller fundamentally compares the desired value with the feedback value to form an error signal, then uses that error to regulate…
Correct answer: comparator- A. All the co-efficients can have zero value
- B. All the co-efficients are always non-zero
- C. Only one of the static error co-efficients has a finite non-zero value
- D. None of the above
Explanation: For a conventional system classified by type, the position, velocity, and acceleration error constants do not all have finite non-zero…
Correct answer: Only one of the static error co-efficients has a finite non-zero value- A. The system is relatively stable
- B. The system is highly stable
- C. The system is highly oscillatory
- D. None of the above
Explanation: A gain margin near unity, or a phase margin near zero, places the system close to the stability limit.
Correct answer: The system is highly oscillatory- A. The time constant of the system
- B. Damping of the system
- C. The gain of the system
- D. The time constant and suppress the oscillations
- E. None of the above
Explanation: Acceleration or second-derivative feedback changes the effective time constant and can improve damping, thereby suppressing oscillations.
Correct answer: The time constant and suppress the oscillations- A. oscillations
- B. step input
- C. negative sign
- D. positive sign
Explanation: Regenerative feedback feeds the returned signal in phase with the input, so it is positive feedback.
Correct answer: positive sign- A. saturation in amplifying stages
- B. loss of gain
- C. vibrations
- D. oscillations
Explanation: Excessive noise can drive amplifier stages beyond their permissible signal range, causing saturation.
Correct answer: saturation in amplifying stages- A. The order of the system
- B. The time constant
- C. The output for any given input
- D. The steady state gain
Explanation: Once the transfer function is known, the output is obtained from Y(s) = G(s)X(s) for any specified input, subject to zero initial…
Correct answer: The output for any given input- A. Band width
- B. Overall gain
- C. Distortion
- D. Instability
Explanation: Negative feedback reduces overall gain, distortion, and sensitivity to parameter changes, while improving stability and increasing…
Correct answer: Band width- A. Ward Leonard control
- B. Field controlled D.C. motor
- C. Stroboscope
- D. Metadyne
Explanation: A field-controlled DC motor can operate as an open-loop system when its speed is controlled by changing field current without measuring…
Correct answer: Field controlled D.C. motor- A. remains unaffected
- B. decreases by the same amount as the gain increase
- C. increases by the sane saaaajajt as the gain decrease
- D. decreases by the same amount as the gain decrease
Explanation: For a feedback amplifier, negative feedback lowers gain while extending bandwidth approximately by the same factor.
Correct answer: increases by the sane saaaajajt as the gain decrease- A. Brain
- B. Hands
- C. Legs
- D. Eyes
Explanation: The eyes sense the path and detect positional error, the brain processes it, and the legs provide the corrective action.
Correct answer: Eyes- A. Auto-pilot for an aircraft
- B. Direct current generator
- C. Car starter
- D. Electric switch
Explanation: An aircraft autopilot measures the aircraft response and feeds corrective information back to the controller, making it a closed-loop…
Correct answer: Auto-pilot for an aircraft