Process Control & Instrumentation Objective Questions – Set 4

Working principle of mercury in glass thermometer is based on the __________ of mercury with increase in temperature.

pH meter has

The time constant of a unity gain, first order plus time delay process is 5 min. If the phase lag at a frequency of 0.2 rad/min is 60°, then the dead time (in minutes) is

Response of a linear control system for a change in set point is called

Bourdon gauges are used for measuring pressure (kg/cm² )

Temperature measurement by optical pyrometer is done above __________ point, which is 1063°C.

A constant volume gas thermometer employing __________ is used to measure sub-zero (i.e., < 0° C) temperature.

Meleoid gauge measures the __________ pressure.

Liquid column manometers are used for measuring the pressure __________ kgf/cm² .

In a shell and tube heat exchanger, the outlet temperature of heating/cooling fluid is the __________ variable.

What is the normal percentage of rhodium in platinum + rhodium element used in the thermocouple ?

Working principle of mercury in glass thermometer is based on volumetric expansion of mercury with increase in temperature. Which of the following undergoes minimum volumetric expansion for a given temperature change ?

The term analogous to voltage in a single tank system is the

Cascade control means

A pyranometer is an instrument used for measuring the

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

__________ stability method uses open loop transfer function.

Very low pressure is expressed in microns(μ), which is equal to __________ mm of Hg coloumn (absolute) at 0°C.

When a bare thermocouple is covered by a protective sheath, the response becomes

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

Stabilising time for the controllers is the time required for the response to reach __________ percent of its ultimate value.

A system with a double pole at the origin is unstable since the corresponding term in the time domain

A first order system with a time constant of 1 min is subjected to frequency response analysis. At an input frequency of 1 radian/min, the phase shift is

Stability of a control system containing a transportation lag can be best analysed by

A photo electric device in which the resistance of the metal is directly proportional to the light striking on it, is known as photo-conductive cell. Photoelectric transducers are used for the measurement of those parameters, which can be used to produce variation in

Thermal wells are used in the temperature measurement to

To increase the speed of response of a pressure spring liquid or gas expansion thermometer, the clearance space between the thermometer bulb and the thermal well should not be filled with

The offset introduced by proportional controller with gain K^c in response of first order system can be reduced by

Bode diagram are generated from output response of the system subjected to which of the following input?

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

Which of the following filled system expansion thermometers has the lowest positive temperature measurement capability ?

Which of the following is not a differential pressure flow meter ?

Thermal conductivity based continuous flue gas analyser makes use of varying thermal conductivity of the constituents of flue gases. Which of the following constituents of flue gases has the maximum thermal conductivity ?

Dilatometer is used to measure

Mass spectrometer is used for the composition analysis of

Mercury thermometer can be used to measure the temperature upto __________ °C.

Hot wire anemometer is used for the measurement of

Routh test

Silver point temperature is __________ °C.

Composition of alloys can be determined by

Optical activity of a solution can be determined using a

Vapour actuated pressure spring thermometer does not require ambient temperature compensation. Ambient temperature compensation is provided in gas or liquid expansion pressure spring thermometer by

Continuous flue gas analyser makes use of paramagnetic properties of some of its constituents, which move towards the strongest part of the magnetic field thus displacing diamagnetic gases. Which of the following gases is diamagnetic ?

An aneroid barometer measures the __________ pressure.

Which of the following does not figure in the list of seven substances selected for international temperature scale ?

Which of the following thermocouples is capable of measuring a temperature of -50°C?

All the thermocouples used for temperature measurement use dissimilar metal

Emf generated in a thermocouple depends on the temperature

A typical example of a physical system with under damped characteristic is a

Radiation thermometer can not measure the temperature