Process Control and Instrumentation MCQs

Question 1

Which of the following controllers has maximum offset?

Accepted Answer

P-controller

Answer

P-I controller

Answer

P-D controller

Answer

P-I-D controller

Question 2

Nichol's chart deals with

Accepted Answer

Closed loop values vs. open loop values

Answer

A.R. vs. phase lag of first order

Answer

A.R. vs. phase lag of second order

Answer

Frequency response values of controllers

Question 3

Helium gas constant volume thermometer is suitable for the measurement of a temperature of __________ °C.

Accepted Answer

< 0

Answer

< 100

Answer

> 0

Answer

> 800

Question 4

A non-linear system will have __________ steady state values.

Accepted Answer

More than one

Answer

One

Answer

Two

Answer

Three

Question 5

__________ is undesirable in thermocouples used in industries,

Accepted Answer

Non-linear relation of emf to temperature

Answer

Linear relation of emf to temperature

Answer

Corrosion resistance

Answer

Oxidation resistance

Question 6

Which of the systems having following transfer functions is stable?

Accepted Answer

$$\frac{1}{{{{	ext{s}}^2} + 2{	ext{s}} + 2}}$$

Answer

$$\frac{1}{{{{	ext{s}}^2} + 2}}$$

Answer

$$\frac{1}{{{{	ext{s}}^2} - 2{	ext{s}} + 3}}$$

Answer

$$\frac{{{	ext{exp}}\left( { - 20{	ext{s}}} ight)}}{{{{	ext{s}}^2} + 2{	ext{s}} - 1}}$$

Question 7

Use of I-control along with P-control facilitates

Accepted Answer

Elimination of offset

Answer

Reduction of offset

Answer

Reduction of stability time

Answer

None of these

Question 8

Which of the following thermocouples is the most suitable for measuring a temperature of about 1600°C in an oxidizing atmosphere?

Accepted Answer

Platinum-platinum + rhodium

Answer

Iron-constantan

Answer

Copper-constantan

Answer

Chromel-alumel

Question 9

Psychrometer determines the

Accepted Answer

Humidity of gases

Answer

Moisture content of solids

Answer

Water of crystallisation

Answer

Hygroscopic nature of solids