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Analysers Flashcards

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1
Q
  1. What is the drawback that occurs in using ion exchange
    chromatography on sulphonated polystyrene resin and
    colourimetry for amino-acid analysis?
    a) Less accuracy
    b) Low resolution
    c) Inconvenient to handle many individual samples
    d) Slow in operation
A

c) Inconvenient to handle many individual samples

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2
Q
  1. Which one of the following methods is the most suitable
    for amino-acid analysis?
    a) Gas chromatography
    b) Ion exchange chromatography
    c) Paper electrophoresis
    d) Resin column chromatography
A

d) Resin column chromatography

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3
Q
  1. Which of the following colour reagents are used in Resin
    column chromatography?
    a) Marquis reagent
    b) Benedict reagent
    c) Ninhydrin
    d) Nessler’s reagent
A

d) Nessler’s reagent

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4
Q
  1. Which of the following amino-acids is measured at a
    wavelength of 440nm using photometric systems?
    a) Proline
    b) Alanine
    c) Glutamine
    d) Valine
A

a) Proline

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5
Q
  1. In Automatic amino-acid analyzer, the sample
    containing ___________ of each amino compound is
    introduced at the top of the ion exchange column.
    a) 1 to 10 µmoles
    b) 1 to 10 moles
    c) 0.05 to 2 moles
    d) 0.05 to 2 µmoles
A

d) 0.05 to 2 µmoles

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6
Q
  1. Which of the following cannot be analysed using resin
    column chromatography?
    a) Peptides
    b) Amines
    c) Amino compounds
    d) Components which are ninhydrin negative
A

d) Components which are ninhydrin negative

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7
Q
  1. Trapped air in pumps of Automatic amino-acid analyzer
    is eliminated using which of the following ways?
    a) Suction pump
    b) De-aerator
    c) Overcome naturally by pump pressure
    d) Using pulse damper
A

b) De-aerator

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8
Q
  1. Amino-acids are distinguishable from each other only by
    one or two atoms in their structure.
    a) True
    b) False
A

a) True

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9
Q
  1. What is the drawback that occurs in using gas
    chromatography for amino-acid analysis?
    a) Costly
    b) Cannot be used for proteins or polypeptides
    c) Slow process
    d) Complex in operation
A

b) Cannot be used for proteins or polypeptides

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10
Q
  1. Resin column chromatography does not involve
    breaking of bonds in amino-acids.
    a) True
    b) False
A

b) False

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11
Q
  1. Which among the following gases have diamagnetic
    property (ability to be repelled by magnetic fields)?
    a) Oxygen
    b) Nitrogen
    c) Nitrogen dioxide
    d) Nitric oxide
A

b) Nitrogen

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12
Q
  1. Which of the following gases have paramagnetic
    property (ability to get attracted to a magnetic field)?
    a) Nitric oxide
    b) Hydrogen
    c) Helium
    d) Nitrogen
A

a) Nitric oxide

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13
Q
  1. The force produced during the operation of
    Paramagnetic oxygen analyzer is proportional to which of the following?
    a) Magnetic susceptibility of sphere
    b) Magnetic susceptibility of surrounding gas
    c) Difference between magnetic susceptibility of sphere and magnetic field strength
    d) Difference between magnetic susceptibility of sphere and that of surrounding gas
A

d) Difference between magnetic susceptibility of sphere and that of surrounding gas

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14
Q
  1. In Paramagnetic oxygen analyzer, the expression for
    magnitude of force produced can be expressed as, F = C (K-KO), where K= magnetic susceptibility of surrounding gas and KO= magnetic susceptibility of sphere. C denotes which of the following?
    a) Magnetic field strength
    b) Magnetic gradient
    c) Function of magnetic field strength and gradient
    d) Magnetic flux
A

c) Function of magnetic field strength and gradient

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15
Q
  1. In Paramagnetic oxygen analyzer, the electrostatic force that is exerted should have which of the following features?
    a) It should be greater than the magnetic field and must be in the same direction
    b) It should be equal to the magnetic field and must be in the same direction
    c) It should be greater than the magnetic field and must be in the opposite direction
    d) It should be equal to the magnetic field and must be in the opposite direction
A

d) It should be equal to the magnetic field and must be in the opposite direction

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16
Q
  1. Which of the following is true about the two charged
    vanes that produce electric field in Paramagnetic oxygen
    analyzer?
    a) Both the vanes should be at higher potential than the
    test body
    b) Both the vanes should have the same potential as the
    test body
    c) One vane should be at higher potential than the test
    body and the other vane should be at lower potential
    d) Both the vanes should be at lower potential than the test body
A

c) One vane should be at higher potential than the test
body and the other vane should be at lower potential

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17
Q
  1. To improve paramagnetic oxygen analyzer, the quartz
    suspension must be replaced with which of the following?
    a) Platinum-iridium
    b) Phosphor-bronze
    c) Gold-palladium
    d) Antimony
A

a) Platinum-iridium

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18
Q
  1. In Paramagnetic oxygen analyzer, when no oxygen is
    present the magnetic force balances torque of the fibre.
    a) True
    b) False
A

a) True

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19
Q
  1. In the Beckman instrument, the flow rate recommended
    when the sample enters through a porous diffusion disc is
    which of the following?
    a) 100-200 cc/min
    b) 50-250 cc/min
    c) 40-60 cc/min
    d) 200-300 cc/min
A

b) 50-250 cc/min

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20
Q
  1. In the Beckman instrument, the flow rate
    recommended when the sample enters directly for rapid
    response is which of the following?
    a) 100-200 cc/min
    b) 50-250 cc/min
    c) 40-60 cc/min
    d) 200-300 cc/min
A

c) 40-60 cc/min

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21
Q
  1. If the oxygen content is not greater than 21%, which of
    the following gases must be used to set the span point?
    a) Oxygen
    b) Dry air
    c) Nitrogen
    d) Hydrogen
A

b) Dry air

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22
Q
  1. Which of the following happens to the magnetic
    susceptibility of gases when the temperature changes?
    a) It increases with increase in temperature
    b) It decreases with increase in temperature
    c) It remains constant with increase in temperature
    d) It remains constant with decrease in temperature
A

b) It decreases with increase in temperature

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23
Q
  1. If the oxygen content is greater than 21%, which of the
    following gases must be used to set the span point?
    a) Oxygen
    b) Dry air
    c) Nitrogen
    d) Hydrogen
A

a) Oxygen

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24
Q
  1. Which of the following does not occur in Hartman and
    Braun oxygen analyzer based on the magnetic wind?
    a) Oxygen is attracted to the magnetic field
    b) Oxygen becomes less paramagnetic due to rise in
    temperature
    c) Resistance change in a resistance connected to the
    Wheatstone bridge occur
    d) Wheatstone Bridge becomes balanced due to
    temperature change
A

d) Wheatstone Bridge becomes balanced due to
temperature change

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25
Q
  1. Which of the following is not a cause of the error that could occur in Hartman and Braun oxygen analyzer based on the magnetic wind?
    a) The filament temperature could be affected by changes in thermal conductivity of the carrier gas
    b) Hydrocarbons in sample stream may react on the
    heated filaments
    c) Gravitation chimney flow effect lead to errors when
    cross tube is horizontal
    d) Combustible gases may react on the heated filaments
A

c) Gravitation chimney flow effect lead to errors when
cross tube is horizontal

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26
Q
  1. Hydrocarbons need to be removed from the sample gas to avoid errors in Hartman and Braun oxygen analyzer.
    a) True
    b) False
A

a) True

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27
Q
  1. Magnetic wind analyzers are also known as which of the
    following?
    a) Thermo-magnetic analyzers
    b) Electro-magnetic analyzers
    c) Thermo-analytical analyzers
    d) Hot wire analyzers
A

a) Thermo-magnetic analyzers

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28
Q
  1. In OXYMAT-M oxygen analyser which of the following is
    usually used as reference gas?
    a) Hydrogen
    b) Nitrogen
    c) Helium
    d) Ambient air
A

d) Ambient air

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29
Q
  1. Which of the following is used in magnetic wind
    instruments to determine the amount of oxygen?
    a) Change in resistance
    b) Change in capacitance
    c) Change in inductance
    d) Change in concentration
A

a) Change in resistance

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30
Q
  1. Which of the following concepts are not used in
    magnetic wind instruments?
    a) Change in resistance due to cooling by magnetic wind
    b) Displacement of membrane by magnetised oxygen
    c) Difference in pressure difference between two gases
    having varying concentration of oxygen
    d) By measuring temperature using thermometer
A

d) By measuring temperature using thermometer

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31
Q
  1. How are the hydrocarbons in the samples removed in
    magnetic wind instruments?
    a) By using a cold trap
    b) By using a filter
    c) By using a semipermeable membrane
    d) By using magnetic effect
A

a) By using a cold trap

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32
Q
  1. Which of the following bridges are used in magnetic
    wind instruments?
    a) Wheatstone bridge
    b) Kelvin’s bridge
    c) Anderson’s bridge
    d) Schering’s bridge
A

a) Wheatstone bridge

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33
Q
  1. The extremely high inertia of the thin membrane in the
    oxygen sensor allows it to rapidly attain equilibrium.
    a) True
    b) False
A

b) False

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34
Q
  1. Which of the following is not true about the galvanic
    method of oxygen analysis?
    a) Electrodes are composed of noble and base metals
    b) It can measure dissolved content of oxygen
    c) Its principle is based on electrolysis
    d) It utilizes an electronic cell
A

c) Its principle is based on electrolysis

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35
Q
  1. Which of the following is true about Hersch cell which is
    one of the arrangements of a galvanic cell?
    a) Cell is spherical in shape
    b) Cathode is made of porous material
    c) Cathode is placed centrally
    d) Cathode is formed by gauze which surrounds the anode
A

d) Cathode is formed by gauze which surrounds the anode

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36
Q
  1. Polarographic cells type of electrochemical method uses
    which of the following concepts?
    a) Cyclic reactions
    b) Exothermic reactions
    c) Reversible reactions
    d) Redox reactions
A

d) Redox reactions

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37
Q
  1. Which of the following methods, is the widely used
    method for trace gas analysis?
    a) Galvanic methods
    b) Conductometric method
    c) Polarographic cells
    d) Thermal conductivity method
A

d) Thermal conductivity method

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38
Q
  1. In the conductometric method, the difference in gas
    conductivity before and after passing sample gas denotes
    which of the following?
    a) Efficiency of the cell
    b) Quantity of reagent
    c) Concentration of gas
    d) Density of the reagent
A

c) Concentration of gas

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39
Q
  1. Conductometric method is not very suitable for
    measuring traces of which of the following gases in ppb
    range?
    a) H2S
    b) SO2
    c) NH3
    d) CO
A

d) CO

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40
Q
  1. Polarographic cells are not sensitive to which of the
    following gases?
    a) Carbon monoxide
    b) Carbon dioxide
    c) Nitrous oxide
    d) Oxygen
A

a) Carbon monoxide

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41
Q
  1. Polarographic cells are used to measure the partial
    pressure of gases only in static gas monitoring systems and
    not in continuous streams.
    a) True
    b) False
A

b) False

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42
Q
  1. In polarographic cell when potential is applied, oxygen is
    reduced at __________ when KCl is present.
    a) Anode
    b) Cathode
    c) Electrolyte
    d) Both the electrode
A

b) Cathode

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43
Q
  1. Nitrogen dioxide can be detected with a paramagnetic
    analyser.
    a) True
    b) False
A

a) True

44
Q
  1. Nitrogen oxide cannot be directly analysed using UV and
    Visible analyzers due to which of the following reasons?
    a) Less accuracy
    b) Very low range
    c) It leads to contamination of the sample
    d) It is transparent in UV visible regions
A

d) It is transparent in UV visible regions

45
Q
  1. Polarographic cells used for measuring the partial
    pressure of oxygen are temperature-sensitive.
    a) True
    b) False
A

a) True

46
Q
  1. How is NO converted to NO2 for analysis in UV and
    Visible analyzers?
    a) Treating sample gas with pressurized oxygen
    b) Treating sample gas with ozone
    c) Treating sample gas with oxygen at low pressure
    d) Treating sample gas with water at high pressure
A

a) Treating sample gas with pressurized oxygen

47
Q
  1. How is NO converted to NO2 for analysis in
    Chemiluminescent analyser?
    a) Treating sample gas with pressurized oxygen
    b) Treating sample gas with ozone
    c) Treating sample gas with oxygen at low pressure
    d) Treating sample gas with water at high pressure
A

b) Treating sample gas with ozone

48
Q
  1. The instruments based on chemiluminescence maintain
    linearity in which of the following ranges?
    a) 1ppb to 100ppb
    b) 100ppb to 1000ppb
    c) 1ppb to 1000ppb
    d) 100ppb to 1000ppb
A

c) 1ppb to 1000ppb

49
Q
  1. During analysis of NO2 using Chemiluminescent
    analyser, why is NO2 not made to react with ozone
    directly?
    a) Less accuracy
    b) It is a slow process
    c) It leads to contamination of the sample
    d) It does not produce luminescence
A

b) It is a slow process

50
Q
  1. How can absorption be enhanced while determining NO
    concentration using CO laser?
    a) By converting NO into NO2
    b) By placing NO in a magnetic field
    c) By using proper monochromators
    d) By using choppers
A

b) By placing NO in a magnetic field

51
Q
  1. Which of the following detectors are generally used for
    detection in NO analysis using CO laser?
    a) Photomultiplier tube
    b) Photovoltaic cell
    c) Liquid nitrogen cooled Ge-Au element
    d) Photo emissive tube
A

c) Liquid nitrogen cooled Ge-Au element

52
Q
  1. Which of the following analyzers are used to measure
    trace amounts of nitrogen oxides in the stratosphere?
    a) Chemiluminescence
    b) CO laser method
    c) Laser opto-acoustic spectroscopy
    d) Colorimetry
A

c) Laser opto-acoustic spectroscopy

53
Q
  1. A pink coloured dye complex is formed when air
    containing NO2 is passed in an absorbing solution
    consisting of __________ and diamine dissolved in the
    acetic acid medium.
    a) Sulphuric acid
    b) Sulphonyl
    c) Sulphonic acid
    d) Sulphanilic acid
A

d) Sulphanilic acid

54
Q
  1. In Laser Opto-acoustic spectroscopy, the IR beam
    excites the molecules to higher states. In which of the
    following ways do the molecules return to the ground
    state?
    a) Collisional de-excitation
    b) Random de-excitation
    c) By spontaneous emission
    d) By stimulated emission
A

a) Collisional de-excitation

55
Q
  1. To monitor oxides of nitrogen in stack effluents, the sample containing oxides of nitrogen is passed through a flask containing solution of H2O2 in sulphuric acid. Nitric acid is formed. The nitrate ions then react with phenoldisulphonic acid to produce blue colour.
    a)True
    b) False
A

b) False

56
Q
  1. Which of the following methods are mainly used in
    combustible gas detection equipment?
    a) Lead acetate tape staining method
    b) Solid state sensor
    c) Gold film sensor
    d) Electrochemical cells
A

b) Solid state sensor

57
Q
  1. Which of the following is not an advantage of
    electrochemical cells used for analysis of H2S?
    a) Portable battery operated instrument
    b) Pocket sized instrument
    c) No pumps are needed
    d) No interference from background gases
A

d) No interference from background gases

58
Q
  1. Which of the following is not an advantage of solid state
    sensor used for analysis of H2S?
    a) No sampling system
    b) It can be used in conditions involving vibration
    c) It can be used in corrosive atmosphere
    d) No interference from background gases
A

d) No interference from background gases

59
Q
  1. Which is the compound that forms the stain in Lead
    Acetate Tape Staining method used for the analysis of
    Hydrogen Sulphide and what is the colour of the stain?
    a) Lead Sulphide, red colour
    b) Lead Sulphide, brown colour
    c) Hydrogen acetate, white colour
    d) Hydrogen acetate, green colour
A

b) Lead Sulphide, brown colour

60
Q
  1. Which of the following methods is not used for
    detection of hydrogen sulphide?
    a) Lead acetate tape staining method
    b) Solid state sensor
    c) Chemiluminescence method
    d) Electrochemical cells
A

c) Chemiluminescence method

61
Q
  1. In solid state sensor, when heated to 150o to 300owhich
    of the following occurs?
    a) Resistance decreases with increase in H2S concentration
    b) Resistance increases with H2S concentration
    c) No change in resistance occurs
    d) Sensor does not respond in this temperature range
A

a) Resistance decreases with increase in H2S concentration

62
Q
  1. In the gold film sensor, the change in resistance is
    proportional to the concentration of H2S.
    a) True
    b) False
A

a) True

63
Q
  1. Which of the following occurs in Electrochemical cells
    used for the detection of hydrogen sulphide?
    a) Change in resistance
    b) Redox reaction
    c) Oxidation-reduction reaction
    d) Change in colour
A

c) Oxidation-reduction reaction

64
Q
  1. Which of the following is not a detector used in mid
    Infrared Spectrophotometer?
    a) Thermopile
    b) Thermistor
    c) Pyroelectric cell
    d) Golay cell
A

d) Golay cell

65
Q
  1. Which of the following is not a component of solid state
    sensor used for detection of hydrogen sulphide?
    a) Heater
    b) Thermistor
    c) Semiconductor film
    d) Photo detector
A

d) Photo detector

66
Q
  1. Which of the following is the chopping frequency used
    for industrial analyzers in the simple infrared analyser for
    gas analysis?
    a) 2-10 Hz
    b) 2-50 Hz
    c) 2-100 Hz
    d) 2-150 Hz
A

a) 2-10 Hz

67
Q
  1. Which of the following is used as a source in the simple
    infrared analyzer for gas analysis?
    a) Tungsten filament lamp
    b) Nernst glower
    c) Hot-wire spiral
    d) Mercury arc lamp
A

c) Hot-wire spiral

68
Q
  1. Why is the use of infrared analyzers limited when it
    comes to the analysis of inorganic compounds?
    a) Slow response occurs
    b) Less accurate results occur
    c) Strong absorption of IR radiation by water
    d) Small range
A

c) Strong absorption of IR radiation by water

69
Q
  1. Vibration excitation occurs only if the sample has
    hetero-atomic molecules.
    a) True
    b) False
A

a) True

70
Q
  1. Which of the following is the chopping frequency used for medical applications in simple infrared analyser for gas analysis?
    a) 2-10 Hz
    b) 2-50 Hz
    c) 2-100 Hz
    d) 2-150 Hz
A

b) 2-50 Hz

71
Q
  1. The movement of diaphragm in simple infrared analyser
    for gas analysis results in which of the following?
    a) Variable resistance
    b) Variable inductance
    c) Variable capacitance
    d) Variable conductance
A

c) Variable capacitance

72
Q
  1. Which of the following is not the drawback of
    conventional infrared analyzers used for gas analysis?
    a) Cell is difficult to maintain
    b) It is expensive to replace
    c) Detector is vibration sensitive
    d) Only one source is used
A

d) Only one source is used

73
Q
  1. Which of the following is used as detector in improved
    infrared analyzer used for gas analysis?
    a) PbSe
    b) MgCl2
    c) ZnCl
    d) CuCl2
A

a) PbSe

74
Q
  1. In calibration of CO2 analyser, in order to establish zero
    calibration which of the following is used as sample?
    a) Oxygen
    b) Hydrogen
    c) Inert gases
    d) Nitrogen
A

c) Inert gases

75
Q
  1. Which of the following is not the characteristics of
    Indium arsenide photovoltaic detector used in infrared
    analyzers for hydrocarbons?
    a) It operates at ambient temperature
    b) Has maximum detectivity at 3.4µm
    c) Sensitivity increases at longer wavelength
    d) It has no response to radiation of wavelength greater
    than 4µm
A

c) Sensitivity increases at longer wavelength

76
Q
  1. Luft detector cell which uses gas as detection
    mechanism is not vibration sensitive.
    a) True
    b) False
A

b) False

77
Q
  1. Which kind of filter is used in improved version of
    infrared gas analyzer at the output end?
    a) Low pass filter
    b) High pass filter
    c) Narrow bandpass filter
    d) Wide bandpass filter
A

c) Narrow bandpass filter

78
Q
  1. Thermal conductivity analyzers cannot be used in which of the following measurements?
    a) Hydrogen in blast furnace gases
    b) Determination of argon in oxygen in the process of air decomposition
    c) Sulphur dioxide in roasting gases in production of
    sulphuric acid
    d) Oxygen from a mixture of oxygen and nitrogen
A

d) Oxygen from a mixture of oxygen and nitrogen

79
Q
  1. Thermistors have positive temperature-coefficient of
    resistance.
    a) True
    b) False
A

b) False

80
Q
  1. Which of the following is not the characteristic of
    thermistors used in thermal conductivity analyzers?
    a) High negative temperature coefficient of resistance
    b) Slow response
    c) Extremely sensitive
    d) Low cost
A

b) Slow response

81
Q
  1. Which among the following elements has the highest
    thermal conductivity?
    a) Nitrogen
    b) Oxygen
    c) Hydrogen
    d) Chlorine
A

c) Hydrogen

82
Q
  1. Which of the following materials are generally not used
    for the construction of filaments in thermal conductivity
    analyzers?
    a) Tungsten
    b) Gold
    c) Platinum
    d) Kovar
A

b) Gold

83
Q
  1. In which of the following conditions can thermal
    conductivity analyzer be used for multi-component
    mixtures?
    a) When all the components have same thermal
    conductivities
    b) When all the components have very different thermal conductivities
    c) When all but one component have same thermal
    conductivities
    d) When all components have very different thermal
    conductivities except two of them which are the same
A

c) When all but one component have same thermal
conductivities

84
Q
  1. How can the high speed of response be obtained in
    thermal conductivity analyzers?
    a) By increasing the pressure of gas surrounding the
    filaments
    b) By reducing the pressure of gas surrounding the
    filaments
    c) By reducing the temperature of gas surrounding the
    filaments
    d) By increasing the temperature of gas surrounding the
    filaments
A

b) By reducing the pressure of gas surrounding the
filaments

85
Q
  1. Which of the following bridges are used in thermal
    conductivity analyzers?
    a) Wheatstone bridge
    b) Kelvin’s bridge
    c) Anderson’s bridge
    d) Schering’s bridge
A

a) Wheatstone bridge

86
Q
  1. Which of the following is generally used as indicators in
    bridges in thermal conductivity analyzers?
    a) Voltmeter
    b) Ammeter
    c) Galvanometer
    d) Wattmeter
A

c) Galvanometer

87
Q
  1. Under which of the following conditions do all real gases
    behave as ideal gases to some extent?
    a) Low temperature and low pressure
    b) Low temperature and high pressure
    c) High temperature and low pressure
    d) Room temperature and normal pressure
A

d) Room temperature and normal pressure

87
Q
  1. Which of the following is the relationship between the
    density of ideal gas and its molecular weight?
    a) Directly proportional
    b) Inversely proportional
    c) Linear
    d) No relation
A

c) Linear

87
Q
  1. Changes in the composition of gas stream give rise to
    changes in thermal conductivity of the gas stream.
    a) True
    b) False
A

a) True

88
Q
  1. Which of the following detectors are not used in
    analyzers based on gas density?
    a) Hot wire
    b) Platinum filament
    c) Thermistor
    d) Thermometer
A

d) Thermometer

89
Q
  1. When would the recorder indicate a zero base line in
    analyzers based on gas density?
    a) When the detector on the sample side is cooler than
    that on the reference side
    b) When the detector on the reference side is cooler than
    that on the sample side
    c) When flow is unbalanced
    d) When both the detectors are equally cooled
A

d) When both the detectors are equally cooled

90
Q
  1. The use of thermistor eliminates the requirement for
    amplification.
    a) True
    b) False
A

a) True

91
Q
  1. In analyzers based on gas density, the unbalance of the
    bridge is linearly proportional to which of the following?
    a) Temperature of sample detector
    b) Pressure at sample detector
    c) Pressure difference between both the detectors
    d) Gas-density difference between both the detectors
A

d) Gas-density difference between both the detectors

92
Q
  1. Which of the following bridges are used in analyzers
    based on gas density?
    a) Wheatstone bridge
    b) Kelvin’s bridge
    c) Anderson’s bridge
    d) Schering’s bridge
A

a) Wheatstone bridge

92
Q
  1. In analyzers based on gas density, if the sample carries a
    gas having a higher density than the detector which of the
    following occurs?
    a) It will cause a net downward flow
    b) It will cause a net upward flow
    c) It splits into two beams
    d) There will be no difference in flow
A

a) It will cause a net downward flow

93
Q
  1. Which of the following is the effective sample volume
    in analyzers based on gas density?
    a) 10 ml
    b) 20 ml
    c) 5 ml
    d) 50 ml
A

c) 5 ml

93
Q
  1. When hot-wires are used as detectors amplification is
    not required.
    a) True
    b) False
A

b) False

94
Q
  1. Gases emit radiation under which of the following
    conditions which can be used for determination of gases?
    a) When mixed with other gases
    b) When kept at suitable temperature
    c) With sufficient electrical excitation and at suitable
    pressures
    d) When exposed to radiation
A

c) With sufficient electrical excitation and at suitable
pressures

95
Q
  1. The characteristic emission of which colour, when
    discharge takes place in a low pressure chamber
    containing gas sample, will indicate the presence of
    nitrogen while using photospectrometer?
    a) Purple
    b) Blue
    c) Pink
    d) Green
A

a) Purple

96
Q
  1. Which of the following measuring technique is utilized
    for measuring nitrogen?
    a) By using a method based on gas density
    b) By using paramagnetic analyzers
    c) By using magnetic wind instruments
    d) By using a photospectrometer where a gas sample is analysed and detected with a photocell
A

d) By using a photospectrometer where a gas sample is analysed and detected with a photocell

97
Q
  1. Sample rates of nitrogen meter can be adjusted by
    doing which of the following?
    a) By modifying the amplifier
    b) With the help of the needle valve
    c) By modifying the detector
    d) By changing chopper frequency
A

b) With the help of the needle valve

97
Q
  1. Which of the following is the normal sampling rate used
    in nitrogen meters?
    a) 13 ml/min
    b) 33 ml/min
    c) 3 ml/min
    d) 43 ml/min
A

c) 3 ml/min

98
Q
  1. Nitrogen meters are calibrated for which of the
    following to measure nitrogen?
    a) Mixture of nitrogen and air
    b) Water saturated mixture of nitrogen and oxygen
    c) Mixture of nitrogen and hydrogen
    d) Nitrogen
A

b) Water saturated mixture of nitrogen and oxygen

98
Q
  1. Why is nitrogen meters generally not calibrated for dry
    gases while measuring nitrogen?
    a) It causes error
    b) Range decreases
    c) Reading tend to be non-linear
    d) It cannot be measured
A

a) It causes error

99
Q
  1. In which of the following ways can nitrogen be
    calibrated for dry gases?
    a) By modifying the amplifier
    b) By adjusting the needle valve
    c) By modifying the detector
    d) By changing chopper frequency
    View Answer
A

b) By adjusting the needle valve

100
Q
  1. The voltage required for striking the discharge in the
    presence of nitrogen is 1500V.
    a) True
    b) False
A

b) False

101
Q
  1. The light output from the discharge tube is interrupted
    by means of a rotating slotted disc.
    a) True
    b) False
A

a) True

Chemical Technician (Analytical Chemistry) (16 decks)

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