Instrumentation and Process Control (IPC)

Question 1

Which of the following is an undesirable dynamic characteristic of an instrument?

A. Reproducibility
B. Dead zone
C. Time lag
D. Static error

Answer 1

C. Time lag

Question 2

Pick out the one which is a first-order instrument

A. Mercury in glass thermometer (w/o any covering or air gap)
B. Bare metallic thermometer
C. Bare vapor pressure thermometer
D. All of the above

Answer 2

D. All of the above

Question 3

Load cells are used for the measurement of

Answer 3

Weight

Question 4

Which of the following is the dynamic characteristics of an instrument?

A. Reproducibility
B. Sensitivity
C. Dead zone
D. Fidelity

Answer 4

D. Fidelity

Question 5

The ____ of a vapor pressure thermometer is a functioning element.

Answer 5

Pointer

Question 6

A negative gain margin expressed in decibels means a/an ______ system.

Answer 6

Unstable

Question 7

Thermistor has a high temperature coefficient of resistivity which is used as the sensing element in resistance thermometer. It is a/an

Answer 7

Solid semiconductor

Question 8

Flapper nozzle is used in a/an _____ controller.

Answer 8

Pneumatic

Question 9

Working principle of radiation pyrometer is based on the

Answer 9

Stefan-Boltzmann Law

Question 10

Which of the following relates the emf generated in a single homogeneous wire to the temperature difference?

A. Peltier effect
B. Thomson effect
C. Seebeck effect
D. None of these

Answer 10

B. Thomson effect

Question 11

Dilute wine was initially used as a thermometric liquid to develop temperature scale. The first empirical temperature scale developed was the ______ scale.

Answer 11

Fahrenheit

Question 12

Which of the following is a desirable characteristic of an instrument?

A. High drift
B. High fidelity
C. High measuring lag
D. Poor reproducibility

Answer 12

B. High fidelity

Question 13

The operation of a rotameter is based on

Answer 13

Variable flow area

Question 14

The temperature of tempering oil baths maintained at 400 deg C during heat treatment of steel is measured by a/an _______ thermocouple.

Answer 14

Iron-constantan

Question 15

Instrumentation in a plant offers the advantage of

A. Greater safety of operation
B. Better quality of product
C. Greater operation economy
D. All of these

Answer 15

D. All of these

Question 16

Need not touch the object whose temperature is being measured

Answer 16

Radiation/infrared pyrometer

Question 17

Thermal conductivity measurement comprises the working principle of a

Answer 17

CO2 analyzer

Question 18

Response of a system to a sinusoidal input is called _____ response.

Answer 18

Frequency

Question 19

The closed loop pole of a stable second order system could be

Answer 19

Both real and negative

Question 20

Smoke density of the flue gas going out of the chimney is measured by a

Answer 20

Photo electric cell

Question 21

Temperature measuring instruments are standardized mostly with ____ points of pure substances.

A. Melting
B. Boiling
C. Both a and b
D. Neither a and b

Answer 21

C. Both a and b

Question 22

Pick out the first-order system from among the following

A. Damped vibrator
B. Mercury in glass thermometer kept in boiling water
C. Interacting system of two tanks in series
D. Non-interacting system of two tanks in series

Answer 22

B. Mercury in glass thermometer kept in boiling water

Question 23

The maximum service temperature for fibre glass used as thermocouple wire insulation material is _____ deg C.

Answer 23

500

Question 24

Which of the following controllers has the least maximum deviation?

A. P controller
B. P-I controller
C. P-I-D controller
D. P-D controller

Answer 24

D. P-D controller

Question 25

Volumetric expansion is the working principle of the ____ thermometers.

Answer 25

Mercury in glass

Question 26

Which of the following measurements can be made by the measurement of emf? A. pH value B. Degree of hydrolysis C. Composition of complex ions D. All of the above

Answer 26

D. All of the above

Question 27

A magnetic flowmeter is A. Based on the principle of Faraday's law B. Capable if measuring the flow rate of slurries and electrolytes C. Based on the linear rekationship between the fluid flow rate and the induced voltage D. All of the above

Answer 27

D. All of the above

Question 28

Zirconia probe is used for the continuous measurement of _________ flue gases going out of the furnace.

Answer 28

Oxygen in

Question 29

Strain gage pressure transducers are used to measure ______ pressures. A. Gage as well as vacuum B. Absolute as well as differential C. Both a and b D. Neither a and b

Answer 29

C. Both a and b

Question 30

Compositional analysis of ______ is done using mass spectrometer.

Answer 30

An isotope

Question 31

The function of a transducer is to

Answer 31

Convert the primary signal into a more useful quantity, usually an electric impulse

Question 32

Which of the ff thermocouples will give yhe highest output for the same value of hot and cold junction temperature? A. Platinum-platinum + rhodium B. Iron-constantan C. Chromel-constantan D. All will give the same output

Answer 32

C. Chromel-constantan

Question 33

______ is undesirable in thermocouples used in industries.

Answer 33

Non-linear relation of emf to temperature

Question 34

Select the correct statement from the following A. The frequency response of a pure capacity process is unbounded. B. The phase lag of a pure time delay system decreases with increasing frequency. C. The amplitude ratio of a pure capacity process is inversely proportional to frequency. D. The amplitude ratio of a pure time delay system decreases with increasing frequency.

Answer 34

C. The amplitude ratio of a pure capacity process is inversely proportional to frequency

Question 34

Continuous shell temperature measurement in a liquid-liquid heat exchanger is done by a

Answer 34

Thermocouple

Question 35

The ____ of a vapor pressures thermometer is a secondary element.

Answer 35

Bourbon tube

Question 36

Emf develiped by a thermocouple while meaduring a temperature of 600 deg C is about 5.5 mV. The type of thermocouple used is

Answer 36

Platinum-platinum+rhodium

Question 37

Relates the absorption and evolution of heat at the junctions of a thermocouple to the current flow in the circuit

Answer 37

Peltier effect

Question 38

In a shell and tube heat exchanger, the flow rate of heating/cooling fluid is the _______ variable.

Answer 38

Manipulated

Question 39

Typical specifications for design stipulates the gain margin and phase margin to be respectively

Answer 39

>1.7 and >30°