IBX - Process Cont. & Instru. Sec. 1 to 7

Question 1

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

Reproducibility
Dead zone
Time lag
Static error

Answer 1

Time lag

Question 2

Which of the following is not the triple point of water?

32°R
273°K
492°R
32°F

Answer 2

32°R

Question 3

Pick out the one which is a first order instrument.

Mercury in glass thermometer (without any covering or air gap).
Bare metallic thermometer.
Bare vapor pressure thermometer.
All (a), (b) and (c).

Answer 3

All (a), (b) and (c).

Question 4

Load cells are used for the measurement of

stress
weight
strain
velocity

Answer 4

weight

Question 5

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

Reproducibility
Sensitivity
Dead zone
Fidelity

Answer 5

Fidelity

Question 6

Pick out the wrong statement.

O2, NO and NO2 exhibit paramagnetic properties as a result of unpaired electrons.
CO2 is the strongest paramagnetic gas.
Paramagnetic susceptibility of gases decreases with temperature.
Paramagnetic susceptibility of gases permits the measurement of their concentration.

Answer 6

CO2 is the strongest paramagnetic gas.

Question 7

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

pointer
bourdon tube
bulb
none of these

Answer 7

pointer

Question 8

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

stable
unstable
critically damped
none of these

Answer 8

unstable

Question 9

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

insulator
conductor
solid semi-conductor
liquid semi-conductor

Answer 9

solid semi-conductor

Question 10

Flapper nozzle is used in a/an __________ controller.

electronic
hydraulic
pneumatic
none of these

Answer 10

pneumatic

Question 11

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

> 1.7 and > 30°
< 1.7 and > 30°
< 1.7 and < 30°
1.7 and < 30°

Answer 11

> 1.7 and > 30°

Question 12

Working principle of radiation pyrometer is based on the

Wien’s law
Kirchoffs law
Stafan-Boltzman law
Seebeck effect

Answer 12

Stafan-Boltzman law

Question 13

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

Peltier effect
Thomson effect
Seebeck effect
none of these

Answer 13

Thomson effect

Question 14

Dilute wine was used as a thermometric liquid initially to develop temperature scale. First emperical temperature scale developed was the __________ scale.

Kelvin
Centigrade
Fahrenheit
Reaumer

Answer 14

Fahrenheit

Question 15

In a single tank system, the transfer function of level to inlet flow rate is

R/TS
R/(TS + 1)
l(TS + l)
1/TS

Answer 15

R/(TS + 1)

Question 16

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

High drift
High fidelity
High measuring lag
Poor reproducibility

Answer 16

High fidelity

Question 17

The operation of a rotameter is based on

variable flow area.
rotation of a turbine.
pressure drop across a nozzle.
pressure at a stagnation point.

Answer 17

variable flow area.

Question 18

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

chromel-alumel
iron-constantan
platinum-platinum/rhodium
none of these.

Answer 18

iron-constantan

Question 19

Instrumentation in a plant offers the advantage of

greater safety of operation
better quality of product
greater operation economy
all (a), (b) and (c)

Answer 19

all (a), (b) and (c)

Question 20

Which of the following temperature measuring instruments need not touch the object whose temperature is being measured?

Radiation/infrared pyrometer
Filled system thermometer
Mercury in glass thermometer
Thermo electric pyrometer

Answer 20

Radiation/infrared pyrometer

Question 21

Thermal conductivity measurement com-prises the working principle of a

CO2 analyser
polarimeter
spectrometer
chromatograph

Answer 21

CO2 analyser

Question 22

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

impluse
unit step
frequency
none of these

Answer 22

frequency

Question 23

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

both real and positive.
complex conjugate with positive real parts.
both real and negative.
one real positive and the other real negative.

Answer 23

both real and negative.

Question 24

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

polarograph
thermal conductivity meter
photo electric cell
chromatograph

Answer 24

photo electric cell

Question 25

Transfer function of transportation lag is e^(TS) e^(-TS) 1/(TS+1) none of these

Answer 25

e^(-TS)

Question 26

Temperature measuring instruments are standardised mostly with __________ points of pure substances. melting boiling both (a) & (b) neither (a) nor (b)

Answer 26

both (a) & (b)

Question 27

Pick out the first order system from among the following. Damped vibrator. Mercury in glass thermometer kept in boiling water. Interacting system of two tanks in series. Non-interacting system of two tanks in series.

Answer 27

Mercury in glass thermometer kept in boiling water.

Question 28

The maximum service temperature for fibre glass used as thermocouple wire insulation material is __________ °C. 250 500 750 1000

Answer 28

500

Question 29

Which of the following controllers has the least maximum deviation? P-controller P-I controller P-I-D controller P-D controller

Answer 29

P-D controller

Question 30

Volumetric expansion is the working principle of the __________ thermometers. mercury in glass constant volume gas vapor pressure bimetallic

Answer 30

mercury in glass

Question 31

Which of the following measurements can be made by the measurement of emf? pH value Degree of hydrolysis Composition of complex ions All (a), (b) & (c)

Answer 31

All (a), (b) & (c)

Question 32

A magnetic flowmeter is based on the principle of Faraday's law. capable of measuring the flow rate of slurries and electrolytes. based on the linear relationship between the fluid flow rate and the induced voltage. all (a), (b) and (c).

Answer 32

all (a), (b) and (c).

Question 33

Zirconia probe is used for the continuous measurment of __________ flue gases going out of the furnace. oxygen in carbon dioxide in carbon monoxide in temperature of

Answer 33

oxygen in

Question 34

Strain gage pressure transducers are used to measure __________ pressures. gage as well as vacuum absolute as well as differential both (a) and (b) neither (a) nor (b)

Answer 34

both (a) and (b)

Question 35

The transfer function for a PID controller is (where, τi is the integral (reset) time and τD is the derivative time.) Kc (1 + τi⋅s + τD )⋅s Kc (1 + τi⋅s + 1/τD⋅s) Kc [1 + τi⋅s + 1/(τD⋅s)] Kc [1 + 1/(τi⋅s) + 1/(τD⋅s)]

Answer 35

Kc (1 + τi⋅s + 1/τD⋅s)

Question 36

Compositional analysis of __________ is done using mass spectrometer. an isotope natural gas a solid an alloy

Answer 36

an isotope

Question 37

The function of a transducer is to modify the input signal. amplify the input signal. convert the primary signal into a more useful quantity, usually an electric impulse. codify/decodify the input signal.

Answer 37

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

Question 38

Nichol's chart deals with A.R.vs. phase lag of first order. A.R. vs. phase lag of second order. closed loop values vs. open loop values. frequency response values of controllers.

Answer 38

closed loop values vs. open loop values.

Question 39

Which of the following thermocouples will give the highest output for the same value of hot and cold junction temperature? Platinum-platinum + rhodium. Iron-constantan. Chromel-constantan. All will give the same output.

Answer 39

Chromel-constantan.

Question 40

A proportional controller with a gain of Kc is used to control a first order process. The offset will increase, if Kc is reduced. Kc is increased. integral control action is introduced. derivative control action is introduced.

Answer 40

Kc is reduced.

Question 41

The symbol for "capillary line" in instrumentation diagram is _._._._._._._ --x--x--x--x-- --//--//--//-- ___________

Answer 41

--x--x--x--x--

Question 42

__________ is undesirable in thermocouples used in industries, Linear relation of emf to temperature Corrosion resistance Oxidation resistance Non-linear relation of emf to temperature

Answer 42

Non-linear relation of emf to temperature

Question 43

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

Answer 43

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

Question 44

For an input forcing function, X(t) = 2t^2, the Laplace transform of this function is 2/s^2 4/s^2 2/s^3 4/s^3

Answer 44

4/s^3

Question 45

Continuous shell temperature measurement in a liquid-liquid heat exchanger is done by a thermocouple reistance thermometer mercury in glass thermometer vapor pressure thermometer

Answer 45

thermocouple

Question 46

The __________ of a vapor pressure thermometer is a secondary element. pointer Bourdon tube bulb none ofthese

Answer 46

Bourdon tube

Question 47

Emf developed by a thermocouple, while measuring a temperature of 600°C is about 5.5 mV. The type of thermocouple used is chromel-alumel iron-constantan platinum-platinum+rhodium either (a), (b) or (c)

Answer 47

platinum-platinum+rhodium

Question 48

Which of the following relates the absorption & evolution of heat at the junctions of a thermocouple to the current flow in the circuit? Seebeck effect Peltier effect Joule heating effect Thomson effect

Answer 48

Peltier effect

Question 49

The second order system with the transfer function [4/(s^2 + 2s +4)] has a damping ratio of 2.0 0.5 1.0 4.0

Answer 49

0.5

Question 50

In a shell and tube heat exchanger, the flow rate of heating/cooling fluid is the __________ variable. load controlled manipulated none of these

Answer 50

manipulated

Question 51

A non-linear chemical system is exemplified by a/an isothermal CSTR mixer non-isothermal CSTR none of these

Answer 51

non-isothermal CSTR

Question 52

The transfer function for an ideal proportional plus reset controller (reset time T) is Kc (1 +1/TS) Kc (1 + TS) Kc (1 + TS) Kc/(1 + S/T)

Answer 52

Kc (1 +1/TS)

Question 53

The frequency response of a first order system, has a phase shift with lower and upper bounds given by - ∞, π/2 -π/2, π/2 -π/2, 0 0, π/2

Answer 53

0, π/2

Question 54

Gas chromatography is used for the measurement of temperature pressure concentration flow rate

Answer 54

concentration

Question 55

Which of the following thermocouples can measure the maximum temperature ? Platinum-rhodium Tungsten-molybdenum Chromel-alumel Iron-constantan

Answer 55

Tungsten-molybdenum

Question 56

Radiation pyrometers as compared to thermocouples has a slower speed of response. can measure higher temperature. can't measure the temperature of moving objects. is more affected by corrosive atmosphere.

Answer 56

can measure higher temperature.

Question 57

Liquid flow rate in a small channel is best measured by a/an weir pitot tube vane meter venturimeter

Answer 57

pitot tube

Question 58

Specific gravity of a liquid can not be measured by a/an anemometer specific gravity bottle pycnometer hydrometer

Answer 58

anemometer

Question 59

__________ temperature scale assigns 0° to the 'ice point' and 80° to the 'steam point'. Celcius Rankine Reumur Farenhite

Answer 59

Reumur

Question 60

Dead zone is the same as time constant. same as transportation lag. maximum change in the variable that does not change the reading of the instrument. none of these.

Answer 60

maximum change in the variable that does not change the reading of the instrument.

Question 61

Which of the following thermometers is not suitable for distant reading upto 60 metres? Vapor pressure thermometer Mercury in glass thermometer Constant volume gas thermometer Resistance thermometer

Answer 61

Mercury in glass thermometer

Question 62

Degree to which an instrument indicates the changes in measured variable without dynamic error is called its speed of response reproducibility fidielity static characteristics

Answer 62

fidielity

Question 63

Thermistors are made of ultra pure metals metal oxides iron-copper alloys nickel-chromium alloys

Answer 63

metal oxides

Question 64

A barometer measures the __________ pressure. absolute gauge absolute as well as gauge dynamic

Answer 64

absolute

Question 65

Humidity of air can be determined by a chromatograph sling psychrometer mass spectrometer polarimeter

Answer 65

sling psychrometer

Question 66

Thermocouple in a thermal well behaves as a true first order system. second order system (overdamped). multiple first order system. second order system (underdamped).

Answer 66

multiple first order system.

Question 67

The transfer function for a P-D controller is Kc(1+τD s) Kc(1 +1/τD s) Kc τD s Kc/τD s

Answer 67

Kc(1+τD s)

Question 68

Bode diagram is a plot of log (AR) vs. log (f) and (Φ) vs. log (f). log (AR) vs. f and log Φ vs.f. AR vs. log (f) and Φ vs. log (f). none of these.

Answer 68

log (AR) vs. log (f) and (Φ) vs. log (f).

Question 69

Working principle of disappearing filament type optical pyrometer is based on the Wien's law Seebeck effect Kirchoff's law Peltier effect

Answer 69

Wien's law

Question 70

Strain gage uses an electrical conductor wire, which when elastically stretched increases in length and reduces in diameter. Both these dimensional changes result in __________ in the electrical resistance of the wire. no change decrease increase exponential decrease

Answer 70

increase

Question 71

Pick out the wrong statement. Proportional controller is normally used for level control in industrial applications. CSTR can be considered as a distributed parameter system. Distributed parameter approach gives partial differential equation. Non-linear behaviour is exemplified by an on-off controller.

Answer 71

CSTR can be considered as a distributed parameter system.

Question 72

Range of hydrogen gas constant volume themometer is __________ °C. -10 to 20 0 to 100 100 - 500 400 - 1000

Answer 72

0 to 100

Question 73

The initial value (t=0) of the unit step response of the transfer function [(s + 1)/(2s + 1)] is 0 1/2 1 2

Answer 73

1/2

Question 74

The __________ of a vapor pressure thermometer is a primary element. pointer Bourdon tube bulb none of these

Answer 74

bulb

Question 75

The time constant of a first order process with resistance R and capacitance C is R + C R - C RC 1/RC

Answer 75

RC

Question 76

A sinusoidal variation in the input passing through a linear first order system becomes more oscillatory (frequency increases). becomes less oscillatory (frequency decreases). gets amplified (magnitude increases). gets attenuated (magnitude decreases).

Answer 76

gets attenuated (magnitude decreases).

Question 77

Nitrogen gas constant volume thermometer is suitable for measuring a temperature of __________ °C. 0-100 < 0 > 100. > 50

Answer 77

> 100.

Question 78

What is the overall transfer function (C/R) of the following block diagram if G = G1⋅G2⋅G3 and H =H1⋅H2. 1/(1+GH) G/(1+GH) H/(1+GH) G/(1-GH)

Answer 78

G/(1+GH)

Question 79

Pick out the most suitable instrument for measuring temperature in the range of-40 to 425°C. mercury thermometer bimetallic thermometer radiation pyrometer none of these

Answer 79

bimetallic thermometer

Question 80

Accurate temperature measurement performance of a radiation pyrometer can not be affected, if the enhancement or attentuation of redia-tion occurs in the sighting path. object and surrounding are at almost the same temperature. object has varying emissivity. object is transparent.

Answer 80

object and surrounding are at almost the same temperature.

Question 81

Relationship between absorption/evolution of heat at the thermocouple junctions and the current flow in the circuit is given by __________ effect. Peltier Thomson Seebeck none of these

Answer 81

Peltier

Question 82

Configuration of Bourdon spring tube is never made of __________ shape. circular semi-circular helical spiral

Answer 82

circular

Question 83

Thermodynamic celcius scale of temperature measurement is defined on the basis of melting point of ice and evaporation temperature of water vapor. defined on the basis of melting point of ice and condensation temperature of water vapor. having an interval of 100° between ice point to steam point. both (b) and (c)

Answer 83

both (b) and (c)

Question 84

According to Bode stability criterian, a system is unstable, if the open loop frequency response exhibits an amplitude ratio exceeding unity at frequency for which phase lag is 0° 45° 90° 180°

Answer 84

180°

Question 85

In a closed loop system, the process to be controlled is an integrating process with transfer function l/2s. The controller proposed to be used in an integral controller with transfer function 1/T1s. When a step change in set point is applied to such a closed loop system, the controlled variable will exhibit overdamped response. underdamped response. undamped response. unstable response.

Answer 85

underdamped response.

Question 86

Resistance of a gas in a vessel is given by (where, P = pressure, V = volume of the vessel, n = no. of moles of the gas, R = gas constant) V/nRT nRT/V nRT/V P/nRT

Answer 86

V/nRT

Question 87

Measurement of pressure in ammonia reactor is done by Bourdon gauge U-tube manometer Inclined tube manometer Pirani guage

Answer 87

Bourdon gauge

Question 88

The fluid used in hydraulic controller is water steam air oil

Answer 88

oil

Question 89

Flow rate of a river is measured by a/an pitot tube vane meter kennison nozzle open weir

Answer 89

vane meter

Question 90

Which of the following thermocouple materials does not contain nickel? Alumel Chromel Constantan None of these.

Answer 90

None of these.

Question 91

Flow rate of those fluids which are insensitive to changes in their density, viscosity or flow velocity profile can be best measured by a magnetic flowmeter pitot tube flow nozzle type flowmeter turbine flowmeter

Answer 91

magnetic flowmeter

Question 92

Identify an unbounded input from inputs whose transfer functions are given below 1 1/S 1/S^2 1/(S^2 + 1)

Answer 92

1/S^2

Question 93

"A control system is unstable, if the open loop frequency response exhibits an amplitude ratio exceeding unity at the crossover frequency." This is __________ criterion. Bode stability Nyquist Routh stability none of these

Answer 93

Bode stability

Question 94

Feed forward controller accounts for the __________ changes. set point load both (a) & (b) neither (a) nor (b)

Answer 94

load

Question 95

Which thermocouple can be used to measure a temperature of around 1400°C ? Copper-constantan Aluminium-chromel Platinum-platinum+rhodium None of these

Answer 95

Platinum-platinum+rhodium

Question 96

Which of the following filled system expansion thermometer has the capability to measure the lowest temperature ? Mercury in glass thermometer Mercury in steel thermometer Alcohol in glass thermometer Fused metal (Na or K) in steel thermometer

Answer 96

Alcohol in glass thermometer

Question 97

Concentration of sugar solution can be determined by the polarimetry flame photometry emission spectroscopy oscillometry

Answer 97

polarimetry

Question 98

In a single tank system, the transfer function of __________ to inlet flow rate is 1/TS+1. outlet flow rate level both (a) & (b) neither (a) nor (b)

Answer 98

outlet flow rate

Question 99

Which of the following can not measure a temperature of 1600°C ? Platinum resistance thermometer Thermocouple Photo-electric pyrometer Radiation pyrometer

Answer 99

Platinum resistance thermometer

Question 100

The temperature range for which copper resistance thermometer can be used is __________ °C. 0 to 150 -200 to 150 350 to 750 500 to 900

Answer 100

-200 to 150

Question 101

Paramagnetism method is not used for the composition determination of __________ in gases. oxygen oxides of nitrogen carbon dioxide any of these

Answer 101

carbon dioxide

Question 102

An amplitude ratio of 0.1 corresponds to __________ decibels. 20 -20 10 -10

Answer 102

-20

Question 103

For increased speed of response of an expansion pressure spring thermometer, the thermometer bulb should have a large area but small mass. high thermal conductivity. small specific heat. all'a', 'b' & 'c'.

Answer 103

all'a', 'b' & 'c'.

Question 104

Pressure of 0.0001 absolute psi can be measured by __________ gauge. Mcloid Pirani thermocouple none of these

Answer 104

Mcloid

Question 105

Pirani gauge is used for the measurement of very high pressure. high vacuum. liquid level under pressure. liquid level at atmospheric pressure

Answer 105

high vacuum.

Question 106

The __________ of the fluid contained in the temperature sensing element (i.e., bulb) of filled system thermometers changes with change in temperature. pressure volume viscosity all (a), (b) and (c)

Answer 106

all (a), (b) and (c)

Question 107

Transfer functions X/Y for which of the following block diagrams is (G1+ G1⋅G2⋅G3)/(1+G2⋅G3)

Answer 107

A

Question 108

The characteristic equation for the control system with a closed loop transfer function G1/1 + G2 is given by 1 + G2 = 0. The characteristic equation for the control system depends only upon the open loop transfer function. determines its stability. is the same for set point or load changes. all 'a', 'b' & 'c'

Answer 108

all 'a', 'b' & 'c'

Question 109

__________ thermometer can not measure sub-zero (< 0° C) temperature, Mercury in glass Bimetallic Vapor pressure Resistance

Answer 109

Bimetallic

Question 110

Starting temperature of optical radiation pyrometer is __________ °C. 800 400 1200 1500

Answer 110

800

Question 111

Liquid argon level in a pressurised storage tank (at 3 kg/cm2 ) is measured by a/an gage glass external float gage differential pressure gage none of these

Answer 111

differential pressure gage

Question 112

Which of the systems having following transfer functions is stable? 1/(s2+ 2) 1/(s2-2s + 3) 1/(s2 + 2s + 2) exp(-20s)/(s2 + 2s-l)

Answer 112

1/(s2 + 2s + 2)

Question 113

What is the dynamic error in a critically damped second order instrument for a ramp input (At) ? 0.5 AT 2 AT sqrt(AT) 1.5 AT

Answer 113

2 AT

Question 114

The transfer function for a first order process with time delay is

Answer 114

[e^(-Td⋅S)]/(T⋅S+1)

Question 115

An ideal PID controller has the transfer function [1 + 1/0.55 + 0.25]. The frequency at which the magnitude ratio of the controller is 1, is 0.5/0.2 0.2/0.5 0.2 x 0.5 1/sqrt(0.2 x 0.5)

Answer 115

1/sqrt(0.2 x 0.5)

Question 116

The deflection of the free end of the bimetallic strips in a bimetallic thermometer with temperature is nearly linear non-linear parabolic hyperbolic

Answer 116

linear

Question 117

Alphatron measures pressure __________ microns. < 1 < 3 > 3 < 0.1

Answer 117

> 3

Question 118

What is the ratio of output amplitude to input amplitude for a sinusoidal forcing function in a first order system? 1 >1 < 1 none of these

Answer 118

< 1

Question 119

The unit step response of the transfer function (2s - 1)/[(3s + 1)(4s + 1)] reaches its final steady state assymptotically after a monotonic increase. a monotonic decrease. initially increasing and then decreasing. increasing decreasing and then increasing.

Answer 119

a monotonic increase.

Question 120

A process is initially at steady state with its output y=l for an input u=l. The input is suddenly changed to 2 at time t=0. The output response is y(t)=1+2t. The transfer function of the process is 2/s 1 + 2/s^2 1 + 2/s (1/s)(1+2/s)

Answer 120

(1/s)(1+2/s)

Question 121

The term analogous to the electrical current in a thermal system is the temperature difference heat flow rate heat content in the system none of these

Answer 121

heat flow rate

Question 122

Reset rate is the another term used for __________ time. dead integral derivative none of these

Answer 122

integral

Question 123

Continuous measurement of moisture in paper is done by sling psychrometer. hair-hygrometer. weighing. high resistance Wheatstone's bridge circuit.

Answer 123

high resistance Wheatstone's bridge circuit.

Question 124

Psychrometer determines the humidity of gases moisture content of solids water of crystallisation hygroscopic nature of solids

Answer 124

humidity of gases

Question 125

Which of the systems having the following transfer function is stable ? 1/(S^2 + 2) 1/(S^2 - 2S + 3) 1/(S^2 + 2S + 2) exp(-20S)/(S^2 + 2S - 1)

Answer 125

1/(S^2 + 2S + 2)

Question 126

The calibration data of a thermocouple with its cold junction at 0°C are given below. Hot Temp (°C) | 0 | 20 | 40 | 60 | 80 |100 | Thermo ermf (mv) |0.00|0.80|1.61|2.43|3.26|4.10| The hot junction of the thermocouple is placed in a bath at 80°C, while its cold junction is at 20°C. What is the emf of thermocouple? 3.26 mv 0.80 mv 2.46 mv 2.43 mv

Answer 126

2.43

Question 127

A mercury barometer measures the __________ pressure. atmospheric gauge vacuum absolute

Answer 127

atmospheric

Question 128

Positioning controllers are used for low loads temperature changes high loads flow rate changes

Answer 128

high loads

Question 129

The amplitude ratio for the sinusoidal response of a __________ is 1. first order system second order system transportation lag none of these

Answer 129

transportation lag

Question 130

The response of two tanks of same size and resistance in series is under damped critically damped over damped none of the above

Answer 130

critically damped

Question 131

The frequency response of a dynamic element shows a constant magnitude ratio at all frequencies. The element exhibits a negative phase shift at all frequencies. The absolute value of the phase shift increases linearly with frequency. The element has the transfer function

Answer 131

e^(-τs)

Question 132

The amplitude ratio for the sinusoidal response of __________ is < 1. transportation lag first order system second order system none of these

Answer 132

first order system

Question 133

Which of the following is a 'contact' pyrometer? resistance pyrometer optical pyrometer radiation pyrometer infra red pyrometer

Answer 133

resistance pyrometer

Question 134

Which of the following is not a speed measuring instrument? Psychrometer Stroboscope Tachometer All (a), (b) and (c)

Answer 134

Psychrometer

Question 135

Measurement of sub-zero Celcius temperature in industry is done most commonly by thermocouples resistance thermometers gas thermometers bi-metallic thermometers

Answer 135

resistance thermometers

Question 136

For the block diagram shown below : [question no. 37 in IBX] The characteristic equation is τl S (τps + 1) + Kc . Kp (τlS + 1) e-τd s = 0 (τmS + 1) (τpS + 1) + Km . Kp e-τd S = 0 τl S(τm S + 1) (τp S + 1) +Kc . Kp . Km (τl s + 1) e-τdS = 0 (τms + 1) (τp s + 1) + Kc . Kp . Km . e-τdS = 0

Answer 136

τl S(τm S + 1) (τp S + 1) +Kc . Kp . Km (τl s + 1) e-τdS = 0

Question 137

Use of I-control along with P-control facilitates elimination of offset reduction of offset reduction of stability time none of these

Answer 137

elimination of offset

Question 138

Turbine flow meters are suitable for very limited flow ranges. cryogenic flow measurements. aerospace and in air borne applications. both (b) and (c).

Answer 138

both (b) and (c).

Question 139

Liquid discharge from a tank or reservoir can not be measured by orifice meters weirs mouthpieces notches

Answer 139

orifice meters

Question 140

Which of the following is not a mechanical pressure sensing element? Bellows Diaphragm Bourdon tube U-tube

Answer 140

U-tube

Question 141

__________ are analysed using a polarograph. Isotonic solutions Solids Liquids Gases

Answer 141

Solids

Question 142

Which of the following judges the accuracy of an instrument? Dead zone Drift Static error None of these

Answer 142

Static error

Question 143

On-off controllers are normally used for low loads temperature changes flow rate changes none of these

Answer 143

low loads

Question 144

Magnetic flowmeters are generally not used for the velocity/flow measurement of hydrocarbons due to their low thermal conductivity. low electrical conductivity. high viscosity index. low flash point.

Answer 144

low electrical conductivity.

Question 145

Which of the following controllers has maximum offset? P-controller P-I controller P-D controller P-I-D controller

Answer 145

P-controller

Question 146

Pressure of 0.01 psi (absolute) can be measured by __________ gauge. ionisation Pirani Mcloid none of these

Answer 146

Mcloid

Question 147

High temperature of around 2000°C of incandescent gas mantles is measured by a/an specially designed thermocouple. optical pyrometer. radiation pyrometer. none of these.

Answer 147

radiation pyrometer.

Question 148

The unit step response of the transfer function 1/(s2 + 2s + 3) has a non-zero slope at the origin. has a damped oscillatory characteristics. is overdamped is unstable

Answer 148

has a damped oscillatory characteristics.

Question 149

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 5π/12 π/6 π/12 π/3

Answer 149

5π/12

Question 150

Which of the following does not figure in the list of seven substances selected for international temperature scale? Ice (F.P) and steam (B.P) Oxygen and sulphur (B.P) Antimony and silver (F.P) Zinc (B.P) and mercury (F.P)

Answer 150

Zinc (B.P) and mercury (F.P)

Question 151

A constant volume gas thermometer employing __________ is used to measure sub-zero (i.e., < 0° C) temperature. helium hydrogen nitrogen none of these

Answer 151

helium

Question 152

pH meter has one cell two cells three cells no cell

Answer 152

two cells

Question 153

Routh test criterion provides information about the actual location of roots. cannot be used to test the stability of a control system containing transportation lag. criterion is not applicable to systems with polynomial characteristic equation. can not determine as to how many roots of the characteristics equation have positive real roots.

Answer 153

cannot be used to test the stability of a control system containing transportation lag.

Question 154

The open loop transfer function of a process is K⋅[(s + 1)(s + 4)/(s + 2)(s +3)]. In the root locus diagram, the poles will be at -1, -4 1, 4 -2, -3 2, 3

Answer 154

-2, -3

Question 155

When a bare thermocouple is covered by a protective sheath, the response becomes faster and oscillatory. faster and non-oscillatory. slower and oscillatory. slower and non-oscillatory.

Answer 155

slower and non-oscillatory.

Question 156

What is the normal percentage of rhodium in platinum + rhodium element used in the thermocouple? 0.1 3 13 29

Answer 156

13

Question 157

Helium gas constant volume thermometer is suitable for the measurement of a temperature of __________ °C. < 100 < 0 > 0 > 800

Answer 157

< 0

Question 158

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

Answer 158

Sinusoidal

Question 159

Which of the following thermocouples is the most suitable for measuring a temperature of about 1600°C in an oxidizing atmosphere? Platinum-platinum + rhodium Iron-constantan Copper-constantan Chromel-alumel

Answer 159

Platinum-platinum + rhodium

Question 160

Mercury thermometer can be used to measure the temperature up to __________ °C. 100 250 350 750

Answer 160

350

Question 161

The transfer function of a process is 1/(16s^2 + 8s + 4). If a step change is introduced into the system, then the response will be under damped critically damped over damped none of these

Answer 161

under damped

Question 162

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 making the volume of thermometer bulb as large as conveniently possible. reducing the volume of the capillary to a minimum. reducing the volume of the receiving element to a minimum. all 'a', 'b' & 'c'.

Answer 162

all 'a', 'b' & 'c'.

Question 163

Which of the following is not a differential pressure flow meter? Rotameter Flow nozzle Orificemeter Venturimeter

Answer 163

Rotameter

Question 164

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? Water Mercury Methyl alcohal Carbon-tetrachloride

Answer 164

Mercury

Question 165

Bourdon gauges are used for measuring pressure (kg/cm2 ) < atmospheric > 2 (gauge) < 2 (gauge) > 10 (absolute)

Answer 165

> 2 (gauge)

Question 166

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 light intensity current flux density voltage

Answer 166

light intensity

Question 167

A typical example of a physical system with under damped characteristic is a U-tube manometer. spring loaded diaphragm valve. CSTR with first order reaction. thermocouple kept immersed in a liquid filled thermowell.

Answer 167

spring loaded diaphragm valve.

Question 168

An aneroid barometer measures the __________ pressure. atmospheric absolute vacuum gage

Answer 168

absolute

Question 169

A bolometer is used for the measurement of thermal radiation. an element which senses optical input and delivers thermal output. both (a) & (b). neither (a) nor (b).

Answer 169

both (a) & (b).

Question 170

Thermal wells are used in the temperature measurement to guard against corrosive and oxidising action on thermocouple materials reduce measuring lag. increase the fidelity. increase the sensitivity.

Answer 170

guard against corrosive and oxidising action on thermocouple materials

Question 171

The offset introduced by proportional controller with gain Kcin response of first order system can be reduced by reducing value of Kc. introducing integral control. introducing derivative control. none of the above.

Answer 171

introducing integral control.

Question 172

A system with a double pole at the origin is unstable since the corresponding term in the time domain is a constant. grows exponentially with time. grows linearly with time. decays linearly with time.

Answer 172

grows linearly with time.

Question 173

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 air a metal powder or graphite oil mercury

Answer 173

air

Question 174

In a second order under damped system, the time required for the response of first reach its ultimate value is called the response time. overshoot (which is a measure of how much the response exceeds the ultimate value) increase with the decrease of damping co-efficient e. decay ratio (which is the ratio of the sizes of successive peaks) is equal to the reciprocal of overshoot. characteristics of a step response is represented by

Answer 174

overshoot (which is a measure of how much the response exceeds the ultimate value) increase with the decrease of damping co-efficient e.

Question 175

In an exothermic chemical reactor, the manipulated variable is the flow rate of coolant reactants product none of these

Answer 175

coolant

Question 176

Very low pressure is expressed in microns(μ), which is equal to __________ mm of Hg coloumn (absolute) at 0°C. 0.0001 0.001 0.01 0.1

Answer 176

0.001

Question 177

The inverse Laplace transform of the function f(s) = 1/S(1+S) is 1 + e^t 1 - e^t 1 + e^-t 1 - e^-t

Answer 177

1 - e^-t

Question 178

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? CO2 N2 O2 CO

Answer 178

CO2

Question 179

Emf generated in a thermocouple depends on the temperature of cold junction only. of hot junction only. difference between hot and cold junctions. difference between cold junction and atmospheric temperature.

Answer 179

difference between hot and cold junctions.

Question 180

Working principle of mercury in glass thermometer is based on the __________ of mercury with increase in temperature. increase of pressure increase of thermal conductivity volumetric expansion differential linear expansion

Answer 180

volumetric expansion

Question 181

Number of poles in a system with transfer function 1/(s^2 + 2s^2 +1) is 2 5 3 1

Answer 181

3

Question 182

Radiation thermometer can not measure the temperature inside a pressure vessel. of an object without coming in contact with it. of liquid oxygen. of moving objects at high temperature.

Answer 182

of liquid oxygen.

Question 183

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

Answer 183

gold

Question 184

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? CO2 O2 NO NO2

Answer 184

CO2

Question 185

Dilatometer is used to measure stress strain deflection contraction/expansion due to changes in temperature

Answer 185

contraction/expansion due to changes in temperature

Question 186

Mass spectrometer is used for the composition analysis of alloys solids isotopes none of these

Answer 186

isotopes

Question 187

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 45° -90° -180° -45°

Answer 187

-45°

Question 188

__________ stability method uses open loop transfer function. Nyquist Mikhalov Ruth none of these

Answer 188

Nyquist

Question 189

A pyranometer is an instrument used for measuring the beam radiation. global radiation. bright sunshine period. none of these.

Answer 189

global radiation.

Question 190

All the thermocouples used for temperature measurement use dissimilar metal strips bars wires beads

Answer 190

wires

Question 191

The transfer function of a first order system is 1/(Ts+1) 1/Ts s/(Ts+1) none of these

Answer 191

1/(Ts+1)

Question 192

Optical activity of a solution can be determined using a polarimeter polarograph dilatometer refractrometer

Answer 192

polarimeter

Question 193

Stability of a control system containing a transportation lag can be best analysed by Routh test root locus methods frequency response methods none of these

Answer 193

frequency response methods

Question 194

Stabilising time for the controllers is the time required for the response to reach __________ percent of its ultimate value. 63.2 87.5 95 100

Answer 194

95

Question 195

Time constant is the time taken by the controlled variable to reach 63.2% of its full change. same as transportation lag. same as dead time. time required by the measured variable to reach 63.2% of its ultimate change.

Answer 195

time taken by the controlled variable to reach 63.2% of its full change.

Question 196

Mercury manometer (U-tube type) exemplifies a __________ order system. zero first second third

Answer 196

second

Question 197

Emf developed by a thermocouple while measuring a temperature of 400°C is 22 mV. The type of thermocouple used is chromel-alumel iron-constantan platinum-rhodium platinum-platinum+rhyodium

Answer 197

iron-constantan

Question 198

Bode stability method uses __________ loop transfer function. open closed either (a) or (b) neither (a) nor (b)

Answer 198

open

Question 199

Working principle of bimetallic thermometers is difference in linear co-efficient of thermal expansion of two strips of different metals welded together. Which of the following has the maximum thermal co-efficient of linear expansion? Nickel Brass Chromel Invar

Answer 199

Brass

Question 200

Which of the following is not a second order instrument? Mercury in glass thermometer with covering. Bare mercury in glass thermometer. Pressure gauge with one bellow, two tubes and a tank. None of these.

Answer 200

Bare mercury in glass thermometer.

Question 201

Small furnace draught is accurately measured by an inclined tube manometer, in which the manometric liquid used most commonly is water carbon tetrachloride paraffin ethylene glycol

Answer 201

paraffin

Question 202

Specific conductance is defined as the reciprocal of resistance in ohms of 1c.c. of liquid at a specified temperature. Its value for distilled water is about __________ micro mho/cm3. 50 100 10 1

Answer 202

1

Question 203

A simple pitot tube measures the average velocity maximum velocity point velocity static pressure

Answer 203

static pressure

Question 204

For a feed back control system to be stable, the roots of the characteristic equation should be real. poles of the closed loop transfer function should lie in the left half of the complex plane. Bode plots of the corresponding open loop transfer function should monotoni-cally decrease. poles of the closed loop transfer function should lie in the right half of the complex plane.

Answer 204

poles of the closed loop transfer function should lie in the left half of the complex plane.

Question 205

A mercury thermometer can not be used to measure the temperature below the freezing point of mercury, which is __________ °C. -38.9 -11.9 -60.9 -80.9

Answer 205

-38.9

Question 206

__________ controller has the maximum stabilising time. P PD PI PID

Answer 206

PI

Question 207

Out of the following temperature measuring instruments, the measurement accuracy will be minimum for the mercury in glass thermometer. optical pyrometer. iron-constantan thermocouple. alcohol filled thermometer.

Answer 207

optical pyrometer.

Question 208

Stalagmometer is used for the measurement of kinematic viscosity surface tension refractive index optical activity

Answer 208

surface tension

Question 209

The deflection in diaphragm (which is used as pressure sensor in pneumatic and electronic instruments) is dependent on the metal thickness, its diameter (d) and shape & number of corrugations. Its deflection is proportional to d d^2 d^3 d^4

Answer 209

d^4

Question 210

Working principle of radiation pyrometer is based on the Wien's law Kirchoffs law stefan-Boltzman law Seebeck effect

Answer 210

stefan-Boltzman law

Question 211

Liquid levels in autocalves are measured by simple float differential float type manometer glass gauge none of these

Answer 211

differential float type manometer

Question 212

E.m.f. generated by thermocouples is of the order of millivolts microvolts volts kilo volts

Answer 212

millivolts

Question 213

A pyrheliometer is an instrument used for measuring the bright sunshine period. beam radiation. diffuse radiation. none of these.

Answer 213

beam radiation.

Question 214

Flow rate through an orifice is __________ the pressure differential. proportional to inversely proportional to the square root of proportional to the square root of inversely proportional to the square of

Answer 214

proportional to the square root of

Question 215

Thermistors are used in __________ devices. voltage measuring temperature measuring temperature compensating both(b)&(c)

Answer 215

both(b)&(c)

Question 216

__________ is the static characteristics of an instrument, Response Tine lag Drift dynamic error

Answer 216

Drift

Question 217

Phase lag of the frequency response of a second order system to a sinusoidal forcing function is 30° is 90° at the most approaches 180° asymptotically is 120°

Answer 217

approaches 180° asymptotically

Question 218

Dead zone in an instrument must be less than __________ percent of the scale. 0.2 1.5 4 8

Answer 218

0.2

Question 219

Emission spectroscopy is used for solids and metal analysis. determining water purity. determination of CO2 in gases. NOxdetermination.

Answer 219

solids and metal analysis.

Question 220

Gas analysis is commonly done using the thermal conductivity cell X-ray diffraction mass spectrometer emission spectrometer

Answer 220

thermal conductivity cell

Question 221

The open loop transfer function of a control system is KR/(1 + TS). This represents a first order system. dead time system. a first order time lag. a second order system.

Answer 221

a first order system.

Question 222

Thermal conductivity measurement is used for the determination of O2 percentage in the flue gas. specific gravity of petrofuels. composition of an alloy. CO2 percentage in the flue gas.

Answer 222

CO2 percentage in the flue gas.

Question 223

Presence of a small amount of water in the organic systems can be determined by the __________ method. electrical conductivity polarimetry emission spectroscopy dielectric constant end loss factor

Answer 223

dielectric constant end loss factor

Question 224

The transfer function of a pure dead time system with dead time τd is 1/(τds + 1) τds + 1 e-τss eτds

Answer 224

e-τss

Question 225

Thermal conductivity cell is the primary element of a/an __________ analyser. oxygen carbon dioxide carbon monoxide sulphur dioxide

Answer 225

carbon dioxide

Question 226

Zirconia probe is used for the measurement of humidity of air. % CO2 in flue gas. % O2 in flue gas. speed of a submarine.

Answer 226

% O2 in flue gas.

Question 227

The root locus method, a pole of a transfer function G(s) is the value of s for which G(s) approaches -1 0 1 ∞

Answer 227

∞

Question 228

__________ type of element is normally not used in the bimetallic thermometers. Flat spiral Bourdon tube Single helix Multiple helix

Answer 228

Bourdon tube

Question 229

Suppose that the gain, time constant and dead time of a process with the following transfer function:Gc(s) = 10 exp( - 0.1s)/(0.5s + 1) are known with a possible error of ± 20% of their values. The largest permissible gain Kc of a proportional controller needs to be calculated below taking the values of process gain, time constant and dead time as 8, 0.6, 0.08 12, 0.6, 0.12 8, 0.6, 0.12 12, 0.4, 0.08

Answer 229

12, 0.6, 0.12

Question 230

Process degree of freedom indicates __________ number of controllers to be used. the maximum the minimum both maximum and the minimum nothing about the

Answer 230

the maximum

Question 231

Characteristic equation is the denominator of __________ loop transfer function. open closed both (a)and (b) neither (a) nor (b)

Answer 231

closed

Question 232

Operating range of a temperature measuring instrument is 800 to 1600°C. It could be a/an __________ pyrometer. radiation optical photoelectric none of these

Answer 232

photoelectric

Question 233

Polarograph is meant for the analysis of gaseous mixture miscible liquids solids isotopes

Answer 233

solids

Question 234

Which of the following fluid flow measuring devices can measure the largest flow rate? V-notch Rotameter Orificemeter Weir

Answer 234

Weir

Question 235

Flow rate of sludge is not measured by a/an orificemeter open weir kennison nozzle both(b)&(c)

Answer 235

both(b)&(c)

Question 236

In a shell and tube heat exchanger, the inlet temperature of heating/cooling fluid is the __________ variable. load manipulated controlled none of these

Answer 236

load

Question 237

Polarisation of light forms the working principle of a polarimeter polarograph chromatograph spectrometer

Answer 237

polarimeter

Question 238

A bimetallic thermometer as compared to industrial mercury in glass thermometer has almost the same temperature measuring range (- 40°C to 450°C). accuracy (± 1% of span). speed of response. all a, b & c.

Answer 238

all a, b & c.

Question 239

Thermal wells used in temperature measurements should have very thick walls. low emissivity. polished surface. high transmissivity of radiation.

Answer 239

high transmissivity of radiation.

Question 240

Which of the following flow-metering instruments is an areameter? Venturimeter Rotameter Pitot tube Hot wire anemometer

Answer 240

Rotameter

Question 241

Out of the following themocouple wire insulating material, the highest temperature rating is for teflon ceramic fibre asbestos fibre glass

Answer 241

ceramic fibre

Question 242

Which is the most suitable instrument for measuring pressure below 3 microns ? Mcleoid gauge Alphatron Ionisation gauge Bourdon guage

Answer 242

Ionisation gauge

Question 243

Routh stability method uses __________ loop transfer function. open closed either (a) or (b) neither (a) nor (b)

Answer 243

closed

Question 244

Pyrometry refers to the measurement of temperature with the mercurial thermometer upto 350°C. directly. which is of higher magnitude. all (a), (b) & (c).

Answer 244

which is of higher magnitude.

Question 245

Photoelectric pyrometers are suitable in the temperature range of __________ °C. 400-1600 800-1600 800-2500 400-1000

Answer 245

800-1600

Question 246

Non-metallic diaphragm used as pressure sensor in instruments is generally made of teflon synthetic rubber bakelite thick paper

Answer 246

synthetic rubber

Question 247

Response of a linear control system for a change in set point is called frequency response transient response servo problem regulator problem

Answer 247

servo problem

Question 248

Hot wire anemometer is used for the measurement of flow rates of fluids. flow rates of granular solids. very high temperature. thermal conductivity of gases.

Answer 248

flow rates of fluids.

Question 249

Which of the following thermocouples has the widest temperature measurement range? Iron-constantan Chromel-alumel Copper-constantan Platinum-platinum/rhodium

Answer 249

Platinum-platinum/rhodium

Question 250

Temperature control of an exothermic chemical reaction taking place in a CSTR is done with the help of cooling water flowing in a jacket around the reactor. The types of valve and controller action to be recommended are air to open valve with the controller direct acting. air to close valve with the controller indirect acting. air to open valve with the controller indirect acting. air to close valve with the controller direct acting.

Answer 250

air to open valve with the controller indirect acting.

Question 251

Bourdon tube is never made of phosphor bronze monel metal stainless steel cast iron

Answer 251

cast iron

Question 252

"An emf of the order of mV is generated when two solutions of different hydrogen ion concentration are separated by a thin glass wall". This is the working principle of a pH meter polarimeter chromatograph polarograph

Answer 252

pH meter

Question 253

The term analogous to voltage in a single tank system is the heat content of the system. liquid volume in the tank. flow rate. level of liquid.

Answer 253

level of liquid.

Question 254

In a shell and tube heat exchanger, the outlet temperature of heating/cooling fluid is the __________ variable. load manipulated controlled none of these

Answer 254

controlled

Question 255

Mcleoid gauge is used to measure the point velocity flow rate vacuum pressure

Answer 255

vacuum

Question 256

What is the Laplace transform of impulse input having magnitude 'X'? X X^2 1/X 1

Answer 256

1

Question 257

Thermocouple is suitable for measuring liquid temperatures only. very high temperatures only. very low temperatures only. both high and low temperatures.

Answer 257

both high and low temperatures.

Question 258

Bimetal strips are not used in bimetallic thermometers. thermocouples. thermostats. relays for opening & closing of electrical circuits.

Answer 258

thermocouples.

Question 259

When the damping co-efficient (ξ) is unity, the system is Overdamped. Critically damped. Underdamped. Highly fluctuating.

Answer 259

Critically damped.

Question 260

Nickel percentage in invar which is an iron-nickel alloy, and is used as a thermocouple material is 12 36 54 68

Answer 260

36

Question 261

Silver point temperature is __________ °C. 760.5 860.5 960.5 1060.5

Answer 261

960.5

Question 262

A non-linear system will have __________ steady state values. one more than one two three

Answer 262

more than one

Question 263

Which of the following is not a variable area flow meter? Piston type meter Rotameter Magnetic flow meter Orifice and tapered plug meter

Answer 263

Magnetic flow meter

Question 264

With increase in temperature, the electrical conductivity of the platinum used in the resistance thermometer increases decreases remains constant increases exponentially

Answer 264

decreases

Question 265

Sub-zero temperature (< 0°C) can be measured by a constant volume gas thermometer employing helium nitrogen hydrogen none of these

Answer 265

helium

Question 266

__________ is an example of distributed parameter system. Tubular reactor CSTR On-off controller none of these

Answer 266

Tubular reactor

Question 267

Which of the following is not classified as a thermo electric pyrometer? Resistance thermometer. Thermocouple. Optical pyrometer (disappearing filament type) Radiation pyrometer

Answer 267

Optical pyrometer (disappearing filament type)

Question 268

Maximum differential pressure in liquid manometer is __________ psi. 20 30 40 50

Answer 268

30

Question 269

Phase margin is equal to 180° - phase lag phase lag - 180° phase lag + 180° phase lag + 90°

Answer 269

180° - phase lag

Question 270

In a feed-back control system G and H denote open loop and close loop transfer functions respectively. The output-input relationship is G/(1 + H) H/(1 +G) G/H H/G

Answer 270

H/(1 +G)

Question 271

Flow rate measurement of hostile acids and alkalis can be most suitably done by a/an venturimeter orificemeter magnetic flow meter hot wire anemometer

Answer 271

magnetic flow meter

Question 272

Compositional analysis of flue gas coming out of a furnace in respect of O2 and CO2% can be continuously done by a/an orsat apparatus thermal conductivity cell zirconia probe chromatograph

Answer 272

thermal conductivity cell

Question 273

Thermisters which have a very high temperature co-efficient of resistivity belong to the class of solid called dielectrics insulators semi conductors conductors

Answer 273

semi conductors

Question 274

The pressure sensing element of elastic type pressure gauge is never made in the form of a bellow diaphragm strip Bourdon tube

Answer 274

strip

Question 275

Liquid flow rate in an open channel can not be measured by a/an orifice meter cipolletti weir rectangular weir V-notch

Answer 275

orifice meter

Question 276

The unit of 'time constant' of a system is the same as that of velocity time (time)-1 none of these

Answer 276

time

Question 277

Which of the following filled system expansion thermometers has the lowest positive temperature measurement capability? Mercury in glass thermometer. Alcohol in glass thermometer. Fused metal (Na or K) in steel thermometer. Nitrogen in steel thermometer.

Answer 277

Alcohol in glass thermometer.

Question 278

Liquid column manometers are used for measuring the pressure __________ kgf/cm2 . > 2(gage) < 3 (gage) < 10 (gage) < atmospheric

Answer 278

< 3 (gage)

Question 279

Cascade control means feed forward control. more than one feed-back loop. on-off control. one feed-back loop.

Answer 279

more than one feed-back loop.

Question 280

The level of a liquid under pressure can be determined using bubbler system differential pressure manometer diaphragm box system air-trap system

Answer 280

differential pressure manometer

Question 281

Temperature measurement range of iron-constantan thermocouple is 0 to 870°C. It can be used to measure sub zero temperature, because at lower temperature emf produced is very low of the order of microvolt. embrittlement of iron occurs. rusting of iron takes place. both (b) and (c).

Answer 281

both (b) and (c).

Question 282

Which of the following is never used as an element of industrial resistance thermometer? Lead Nickel Copper 30% iron + 70% nickel

Answer 282

Lead

Question 283

Which of the following shows maximum dip effect (indicating reverse direction of temperature change)? Mercury thermometer Radiation pyrometer Bimetallic thermometer Thermocouple

Answer 283

Mercury thermometer

Question 284

A stable system is the one for which the output response is bounded for all bounded input. which exhibits an unbounded response to a bounded input which satisfies the conditions for a servo problem. none of these.

Answer 284

for which the output response is bounded for all bounded input.

Question 285

The Laplace transform of exp(at), where a > 0, is defined only for the Laplace parameter, s > a since the function is exponential. the Laplace transform of integral of exp(at) has finite values only for s > a. the Laplace transform integral of exp(at) has initial values only for s > a. the function exp(at) is piece-wise continuous only for s > a.

Answer 285

the Laplace transform of integral of exp(at) has finite values only for s > a.

Question 286

Meleoid gauge measures the __________ pressure. positive sub-atmospheric very high atmospheric

Answer 286

sub-atmospheric

Question 287

Which of the following thermocouples is capable of measuring a temperature of -50°C? Platinum - platinum + rhodium Chromel - alumel Iron-constantan Copper - constantan

Answer 287

Platinum - platinum + rhodium

Question 288

Platinum resistance thermometer can be used upto antimony point which is __________ °C, and is the temperature of equilibrium between solid antimony & liquid antimony at normal atmospheric pressure. 961.93 630.74 1064.43 1261.93

Answer 288

630.74

Question 289

Change of angle of refraction with composition comprises the working principle of a polarimeter polarograph spectrometer refractrometer

Answer 289

refractrometer

Question 290

Which of the following instruments is not used for measuring sub-zero (<0°) temperatures? Platinum resistance thermometer Mercury in glass thermometer Vapor pressure thermometer Radiation pyrometer

Answer 290

Radiation pyrometer

Question 291

Which of the following is not suitable for measuring the temperature of a red hot object in the range of 800 - 1600°C ? Optical pyrometer Radiation pyrometer Photoelectric pyrometer Thermocouples

Answer 291

Thermocouples

Question 292

Flame photometry is used for the determination of compositional analysis of solids alkali metals natural gas isotopes

Answer 292

alkali metals

Question 293

Reference points i.e., ice point and steam point in Reaumer temperature scale are respectively - 273° & 80° 0° & 80° 32° & 460° 32° & 80°

Answer 293

0° & 80°

Question 294

Which of the following is not a composition measuring instrument? Thermal conductivity cell Mass spectrometer Polarograph Hot wire anemometer

Answer 294

Hot wire anemometer

Question 295

Emf developed by a thermocouple while measuring a temperature of 800°C is about 31 mV. The type of thermocouple used is chromel-alumel iron-constantan platinum-platinum+rhodium none of these.

Answer 295

chromel-alumel

Question 296

Which of the following thermocouples is incapable of measuring sub-zero (i.e., < 0°C) temperature? Chromel-alumel Iron-constantan Platinum-platinum + rhodium Copper-constantan

Answer 296

Platinum-platinum + rhodium

Question 297

Platinum resistance thermometer is the international standard for temperature measurement between triple point of hydrogen and freezing point of antimony 13.81°K to 903.9°K both (a) and (b) neither (a) nor (b)

Answer 297

both (a) and (b)

Question 298

On-off control which is a special case of proportional control, has a band width of about __________ percent. 100 75 25 0

Answer 298

0

Question 299

The thermal emf-temperature relationship of most thermocouples is linear parabolic exponential square root

Answer 299

parabolic

Question 300

Which is the strongest paramagnetic gas? CO2 O2 NO NO2

Answer 300

O2

Question 301

In Bode plot, A.R. vs. w is plotted on a/an __________ graph paper. log-lag triangular ordinary semi-log

Answer 301

log-lag

Question 302

A first order system with unity gain and time constant τ is subjected to a sinusoidal input of frequency w = 1/τ. The amplitude ratio for this system is 1 0.5 1/sqrt(2) 0.25

Answer 302

1/sqrt(2)

Question 303

For measuring the temperature of a red hot furnace, which is the most suitable instrument? Platinum resistance thermometer Thermocouple Optical pyrometer Bimetallic thermometer

Answer 303

Optical pyrometer

Question 304

Continuous measurement of specific gravity of a liquid is done by hydrometer contact-type electric indicators displacement meter both (a) and (c)

Answer 304

both (a) and (c)

Question 305

Stroboscope is used for the measurement of rpm of a flywheel frequency of light depression of freezing point liquid level under pressure

Answer 305

rpm of a flywheel

Question 306

In second order underdamped system, decay ratio = overshoot decay ratio = (overshoot)^2 overshoot increases for increasing damping co-efficient. large damping co-efficient means smaller damping.

Answer 306

decay ratio = (overshoot)^2

Question 307

Dome temperature of blast furnace stove is most accurately measured by a radiation pyrometer. platinum-platinum/rhodium ther-mocuple. iron-constantan thermocouple. platinum resistance thermometer.

Answer 307

platinum-platinum/rhodium ther-mocuple.

Question 308

Phase lag of the sinusoidal response of a first order system is 120° 30° 180° 90°

Answer 308

90°

Question 309

Continuous measurement of moisture content of paper in paper industry is done by measuring the thermal conductivity through the paper electrical resistance through the paper magnetic susceptibility none of these

Answer 309

electrical resistance through the paper

Question 310

Thermal well made of __________ gives the fastest speed of response, while measuring temperature by thermocouples. steel vycor (a glass) nichrome inconel

Answer 310

vycor (a glass)

Question 311

Pick out the wrong statement. There is no transfer lag for a single first order system. Stirred tank with a water jacket exemplifies an interacting system. Transfer lag is a characteristics of all higher order systems (other than first order systems). Transfer lag decreases as the number of stages decreases.

Answer 311

Transfer lag decreases as the number of stages decreases.

Question 312

Working principle of mercury in glass thermometer is volumetric expansion. pressure rise with temperature. linear expansion. none of these.

Answer 312

volumetric expansion.

Question 313

The frequency at which maximum amplitude ratio is attained is called the __________ frequency. corner resonant cross-over natural

Answer 313

resonant

Question 314

Which of the following can measure temperatures in the range of - 20 to 300°C ? Mercury in glass thermometer Vapor pressure thermometer Resistance thermometer None of these.

Answer 314

None of these.

Question 315

If response of a control system is to be free of offset and oscillation, the most suitable controller is proportional controller. proportional-derivative(PD)controller. proportional-integral (PI) controller. proportional integral-derivative (PID) controller.

Answer 315

proportional integral-derivative (PID) controller.

Question 316

Conversion formula for converting amplitude ratio (AR) into decibels is Decibel = 20 log 10 (AR) Decibel = 20 log e (AR) Decibel = 20 log 10 (AR)^0.5 Decibel = 20 log e (AR)^0.5

Answer 316

Decibel = 20 log 10 (AR)

Question 317

A manometer measures the __________ pressure. atmospheric absolute gauge none of these

Answer 317

gauge

Question 318

Normal mercury thermometer can be used to measure a temperature of about 300°C. However, its maximum temperature measurement range can be increased upto about 500°C by filling nitrogen under pressure in the stem. increasing the diameter of the tube. using steel tube in place of glass tube. accounting for the tube expansion.

Answer 318

filling nitrogen under pressure in the stem.

Question 319

Minute depression of freezing point of a liquid solvent on addition of a solid solute can be best measured by a Beckman thermometer dilatometer mercury thermometer bimetallic thermometer

Answer 319

Beckman thermometer

Question 320

Temperature of __________ can not be measured by an optical or radiation pyrometer. hot blast (air) from stoves molten slag flowing out of blast furnace combustion space in boilers rotary limestone calcination kiln

Answer 320

hot blast (air) from stoves

Question 321

Gain margin is equal to the amplitude ratio reciprocal of amplitude ratio gain in P controller gain in P-I controller

Answer 321

reciprocal of amplitude ratio

Question 322

A system with transfer function 2S/4S + 1 is of __________ order. zero 1st 2nd 3rd

Answer 322

1st

Question 323

In Bode plot, Φ vs ω is plotted on a/an __________ graph paper. log-log ordinary semi-log triangular

Answer 323

log-log

Question 324

Temperature of molten pig iron (1450°C) and molten slag (1500°C) flowing out of a blast furnace is measured by a/an chromel-alumel thermocouple optical pyrometer radiation pyrometer either (b) or (c)

Answer 324

either (b) or (c)

Question 325

For two non-interacting first order systems connected in series, the overall transfer function is the __________ of the individual transfer functions. product ratio sum difference

Answer 325

product

Question 326

Ordinary mercury in glass thermometer is used for measuring temperature upto 120°C. However, for measuring higher temperature upto __________ °C, thermometer is made by filling nitrogen under pressure above the mercury, which stops the evaporation of mercury and reduces the chance of broken thread of mercury. 250 350 550 700

Answer 326

550

Question 327

Mercury thermometer is commonly used for low temperature measruement. The freezing point and boiling point of mercury are respectively __________ °C. - 39 and 350 - 51 and 439 - 79 and 395 - 10 and 425

Answer 327

- 39 and 350

Question 328

Which of the following thermocouples has the least temperature measurement range? Copper-constantan Chromel-alumel Platinum-platinum/rhodium Iron-constantan

Answer 328

Copper-constantan

Question 329

Composition of natural gas is determined by the Haldane apparatus mass spectrometer chromatograph both (b) and (c)

Answer 329

both (b) and (c)