All Free Electrical Engineering MCQs with Answers

• A. Root locus
• B. Bode
• C. Nyquist
• D. Nichols

Explanation: The root-locus technique rapidly relates gain to closed-loop pole locations, allowing both stability and transient characteristics to be…

• A. system stability
• B. system gain
• C. system stability and gain
• D. none of the above

Explanation: Negative feedback reduces the overall closed-loop gain, approximately to the forward gain divided by one plus loop gain.

• A. small bandwidth
• B. negative time constant
• C. large negative transfer function pole
• D. none of the above

Explanation: A well-designed first-order system has its pole on the negative real axis, and a pole farther to the left gives a faster response.

• A. Bode-Nyquist stability methods
• B. Transfer functions
• C. Root locus design
• D. State model representatives

Explanation: State-space models use state equations that can include time-dependent coefficients, so they apply to time-varying systems.

• A. pressure signal to electric signal
• B. pressure signal to position change
• C. electric signal to pressure signal
• D. position change to pressure signal
• E. none of the above

Explanation: In a pneumatic control system, the valve actuator receives a pneumatic pressure signal and converts it into mechanical stem or plug…

• A. is independent of frequency
• B. is inverseh'proportional to frequency
• C. increases linearly with frequency
• D. decreases linearly with frequency

Explanation: A transportation delay of T seconds has transfer function e^(-sT), whose phase is -ωT radians.

• A. not necessarily stable
• B. stable
• C. unstable
• D. always unstable
• E. any of the above

Explanation: A bounded response to one step input does not by itself prove overall stability, because other inputs or unobserved system modes may still…

• A. parabolic
• B. ramp
• C. impulse
• D. step

Explanation: A unit ramp input has a constant rate of change, so its steady-state tracking error is governed by the velocity error constant.

• A. no net pole
• B. net pole
• C. simple pole
• D. two poles

Explanation: System type is the number of net poles at the origin in the open-loop transfer function.

• A. acceleration
• B. velocity
• C. position
• D. all of the above

Explanation: Static error coefficients quantify steady-state performance for position, velocity, and acceleration inputs.

• A. capacitance
• B. reciprocal of capacitance
• C. current
• D. resistance

Explanation: In the force-voltage analogy, force corresponds to voltage and velocity to current.

• A. Laplace Transform and Fourier Integral
• B. Laplace Transform
• C. Fourier Integral
• D. Either B. or C.

Explanation: The Laplace transform provides the general time-domain to complex-frequency-domain relation, while the Fourier integral gives the direct…

• A. no pole
• B. net pole
• C. simple pole
• D. two poles

Explanation: A type 1 system has one net pole at the origin. A single pole at the origin is called a simple pole.

• A. smaller damping ratio
• B. larger damping ratio
• C. constant damping ratio
• D. none of the above

Explanation: Increasing loop gain commonly moves the dominant closed-loop poles toward lower damping, producing more overshoot and oscillation.

• A. reduced velocity lag error
• B. increased velocity lag error
• C. increased speed of response
• D. reduced time constant of the system

Explanation: For a typical position servo, the velocity error is proportional to the friction coefficient and inversely related to loop gain, so…

• A. Phase-lead
• B. Phase-lag
• C. Both A. and B.
• D. Either A. and B.
• E. None of the above

Explanation: A phase-lead compensator adds positive phase near the crossover frequency, increasing phase margin and effective damping.

• A. The range of air output as measured variable varies from maximum to minimum
• B. The range of measured variables from set value
• C. The range of measured variables through which the air output changes from maximum to minimum
• D. Any of the above
• E. None of the above

Explanation: Proportional band is the range of measured-variable values over which the controller output moves through its full range, usually from…

• A. Microsyn
• B. Selsyn
• C. Synchro-resolver
• D. Synchro-transformer

Explanation: A synchro-resolver converts angular information between coordinate systems, such as resolving shaft position into sine and cosine…

• A. lag at all frequencies
• B. lag at high frequencies and lead at low frequencies
• C. lag at low frequencies and lead at high frequencies
• D. none of the above

Explanation: A lag-lead network contributes lag at low frequencies and lead at high frequencies, combining improved steady-state accuracy with improved…

• A. reduces damping
• B. reduces the gain margin
• C. increases input noise
• D. increases error

Explanation: Differentiation magnifies high-frequency components, including unwanted measurement noise.