Process Control Flashcards
Which of the following is an undesirable dynamic characteristic of an instrument?
A. Reproducibility
B. Dead zone
C. Time lag
D. Static error
C. Time lag
Pick out the one which is a first order instrument.
A.Mercury in glass thermometer (without any
covering or air gap)
B. Bare metallic thermometer
C. Bare vapor pressure thermometer
D. All of the above
D. All of the above
Load cells are used for the measurement of
A. stress
B. weight
C. strain
D. velocity
B. weight
Which of the following is the dynamic characteristics
of an instrument?
A. Reproducibility
B. Sensitivity
C. Dead zone
D. Fidelity
D. Fidelity
The ____ of a vapor pressure thermometer
is a functioning element.
A. pointer
B. bourdon tube
C. bulb
D. none of these
A. pointer
A negative gain margin expressed in decibels
means a/an system.
A. stable
B. unstable
C. critically damped
D. none of these
B. unstable
Thermistor has a high temperature coefficient of
resistivity which is used as the sensing element in
resistance thermometer. It is a/an
A. insulator
B. conductor
C. solid semiconductor
D. liquid semiconductor
C. solid semiconductor
Flapper nozzle is used in a/an
controller.
A. electronic
B. hydraulic
C. pneumatic
D. none of these
C. pneumatic
Working principle of radiation pyrometer is based on
the
A. Wien’s law
B. Kirchoff’s law
C. Stefan-Boltzman law
D. Seebeck effect
C. Stefan-Boltzman law
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
B. Thomson effect
Dilute wine was initially used as a thermometric liquid to
develop a temperature scale. The first empirical temperature scale developed
was the ____ scale.
A. Kelvin
B. Centigrade
C. Fahrenheit
D. Reaumer
C. Fahrenheit
Which of the following is a desirable characteristic
of an instrument?
A. High drift
B. High fidelity
C. High measuring lag
D. Poor reproducibility
B. High fidelity
The operation of a rotameter is based on
A. variable flow area.
B. rotation of a turbine.
C. pressure drop across a nozzle.
D. pressure at a stagnation point
A. variable flow area.
The temperature of tempering oil baths maintained at 400°C during heat treatment of steel is measured
by a/an _____ thermocouple.
A. chromel-alumel
B. iron-constantan
C. platinum-platinum/rhodium
D. none of these
B. iron-constantan
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
D. all of these
Which of the following temperature measuring
instruments need not touch the object whose
temperature is being measured?
A. Radiation/infrared pyrometer
B. Filled system thermometer
C. Mercury in glass thermometer
D. Thermo-electric pyromete
A. Radiation/infrared pyrometer