EE FC - Feedback Control System

What is a controller?

• Sensor

• Comparator

• Clipper

• Amplifier

Which of the following is the input to a controller?

• Error signal

• Servo signal

The effect of adding feedback makes the system__________.

• Linear

• Non-linear

• Time variant

• Time invariant

In an automatic control system which of the following elements is not used?

• Error detector

• Final control element

• Sensor

• Oscillator

Which of the following are the characteristics of regenerative feedback?

• Stable

• Zero damping

• Least sensitive to parameter variations

• None of the mentioned

The output of a feedback control system must be a function

• Reference and output

• Reference and input

• Input and feedback signal

• Output and feedback signal

The Laplace transforms of the function e^^−2t is

• 1/2s

• s+2

• 1/(s+2)

• 2s

A control system whose step response is -0.5(1+e^^-2t) is cascaded to another control block whose impulse response is

e^-t. What is the transfer function of the cascaded combination?

• 1/(s+2)(s+1)

• 1/(s+1)s

• 1/(s+3)

• 0.5/(s+1)(s+2)

Signal flow graphs in control system is/are;

• They apply to linear systems

• The equation obtained may or may not be in the form of cause or effect

• Arrows are not important in the graph

• They cannot be converted back to block diagram

Transfer function of the system is defined as the ratio of Laplace output to Laplace input considering initial conditions________.

• 0

•  1

• 2

• infinite