1. Write whether True or False.

Practical control systems are designed to perform as slightly underdamped second order systems.

A DC tachogenerator produces voltage that is proportional to the rotor speed.

Velocity error (due to unit ramp input) of a type-O closed-loop control system is always zero.

Characteristics of a system is dominantly determined by the roots near the imaginary axis on s-plane.

To determine a transfer function from input-output relation of the system, all initial conditions are assumed zero.

Root locus technique informs about the variation of gain with system stability in a negative feedback closed-loop system.

While designing practical systems,integrator is placed slightly to the left of origin.

Consider the block diagram shown in Figure 1.

<img src='./qimages/11343-2a.jpg'>

Determine the transfer functions with and with =0.

Use block diagram reduction technique in Figure 2 below and determine the transfer function.

<img src='./qimages/11343-2b.jpg'>

3. With the help of a schematic diagram, explain the working of a synchro error detector. Draw the typical waveforms.

When the first term in any row of the Routh array is zero while rest of the row has at least one non-zero term, Routh's test breaks down. How do you overcome this situation?

An open-loop system is given as

k 6s 25)

Using Routh criterion, determine the value of k for which the closed-loop unity feedback system will have sustained oscillation. Also determine the frequency of sustained oscillation in rad/sec.

5. Explain the significance of step, ramp, parabolic and impulse signals as test input signals. Also derive the corresponding Laplace functions.

Describe the role of proportional, integral and derivative control in open-loop process control.

Explain the working of on-off controller.

7. Write short notes on any two of the following:

Potentiometer as Error Detector

Op-Amp as Derivative Controller

Stepper Motor