Process Control and Instrumentation MCQs

Question 1

Transfer function of transportation lag is

Accepted Answer

E -Ts

Answer

E Ts

Answer

$$\frac{1}{{{	ext{Ts}} + 1}}$$

Answer

None of these

Question 2

A control system is unstable, if the open loop frequency response exhibits an amplitude ratio exceeding unity at the crossover frequency. This is __________ criterion.

Accepted Answer

Bode stability

Answer

Nyquist

Answer

Routh stability

Answer

None of these

Question 3

The level of a liquid under pressure can be determined using

Accepted Answer

Differential pressure manometer

Answer

Bubbler system

Answer

Diaphragm box system

Answer

Air-trap system

Question 4

Phase lag of the frequency response of a second order system to a sinusoidal forcing function

Accepted Answer

Approaches 180° asymptotically

Answer

Is 30°

Answer

Is 90° at the most

Answer

Is 120°

Question 5

In an exothermic chemical reactor, the manipulated variable is the flow rate of

Accepted Answer

Coolant

Answer

Reactants

Answer

Product

Answer

None of these

Question 6

Sub-zero temperature (< 0°C) can be measured by a constant volume gas thermometer employing

Accepted Answer

Helium

Answer

Nitrogen

Answer

Hydrogen

Answer

None of these

Question 7

Pick out the wrong statement

Accepted Answer

CSTR can be considered as a distributed parameter system

Answer

Proportional controller is normally used for level control in industrial applications

Answer

Distributed parameter approach gives partial differential equation

Answer

Non-linear behaviour is exemplified by an on-off controller

Question 8

Flame photometry is used for the determination of compositional analysis of

Accepted Answer

Alkali metals

Answer

Solids

Answer

Natural gas

Answer

Isotopes

Question 9

Thermal conductivity measurement comprises the working principle of a

Accepted Answer

CO 2 analyser

Answer

Polarimeter

Answer

Spectrometer

Answer

Chromatograph