ME or MEng Master of Engineering Control Systems and Dynamics

Question 1

How is the transfer function of a linear time-invariant system formally defined?

Accepted Answer

The ratio of the Laplace transform of output to input with zero initial conditions

Answer

The ratio of output to input in the time domain

Answer

The ratio of input to output in the frequency domain

Answer

The convolution of the input and output signals

Question 2

In a closed-loop control system, what is the primary purpose of feedback?

Accepted Answer

To compare the output with the desired input and reduce error

Answer

To increase the system's open-loop gain

Answer

To eliminate the need for a controller

Answer

To increase system bandwidth without affecting stability

Question 3

A PID controller combines which three control actions?

Accepted Answer

Proportional, Integral, and Derivative

Answer

Position, Inertia, and Damping

Answer

Phase, Impedance, and Damping

Answer

Proportional, Impedance, and Differential

Question 4

What is the steady-state error to a step input for a Type 1 control system?

Accepted Answer

Zero

Answer

A constant non-zero value

Answer

Infinite

Answer

Dependent on system gain

Question 5

In the s-domain, what is the transfer function of an ideal differentiator?

Accepted Answer

s

Answer

1/s

Answer

1/s²

Answer

s²

Question 6

What information does a Bode plot provide about a control system?

Accepted Answer

Magnitude and phase of the frequency response versus frequency

Answer

Root locations as open-loop gain varies

Answer

Time-domain step response of the closed-loop system

Answer

Nyquist contour mapping in the complex plane

Question 7

The characteristic equation of a control system is obtained by setting which expression to zero?

Accepted Answer

The denominator of the closed-loop transfer function

Answer

The numerator of the open-loop transfer function

Answer

The numerator of the closed-loop transfer function

Answer

The gain of the proportional controller