Analysers Flashcards
(107 cards)
1
Q
- 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
2
Q
- 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
3
Q
- 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
4
Q
- 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
5
Q
- 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
6
Q
- 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
7
Q
- 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
8
Q
- Amino-acids are distinguishable from each other only by
one or two atoms in their structure.
a) True
b) False
A
a) True
9
Q
- 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
10
Q
- Resin column chromatography does not involve
breaking of bonds in amino-acids.
a) True
b) False
A
b) False
11
Q
- 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
12
Q
- 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
13
Q
- 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
14
Q
- 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
15
Q
- 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
16
Q
- 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
17
Q
- 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
18
Q
- In Paramagnetic oxygen analyzer, when no oxygen is
present the magnetic force balances torque of the fibre.
a) True
b) False
A
a) True
19
Q
- 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
20
Q
- 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
21
Q
- 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
22
Q
- 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
23
Q
- 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
24
Q
- 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
25
2. 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
c) Gravitation chimney flow effect lead to errors when
cross tube is horizontal
26
3. Hydrocarbons need to be removed from the sample gas to avoid errors in Hartman and Braun oxygen analyzer.
a) True
b) False
a) True
27
4. 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) Thermo-magnetic analyzers
28
5. In OXYMAT-M oxygen analyser which of the following is
usually used as reference gas?
a) Hydrogen
b) Nitrogen
c) Helium
d) Ambient air
d) Ambient air
29
6. 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) Change in resistance
30
7. 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
d) By measuring temperature using thermometer
31
8. 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) By using a cold trap
32
9. 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) Wheatstone bridge
33
10. The extremely high inertia of the thin membrane in the
oxygen sensor allows it to rapidly attain equilibrium.
a) True
b) False
b) False
34
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
c) Its principle is based on electrolysis
35
2. 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
d) Cathode is formed by gauze which surrounds the anode
36
3. Polarographic cells type of electrochemical method uses
which of the following concepts?
a) Cyclic reactions
b) Exothermic reactions
c) Reversible reactions
d) Redox reactions
d) Redox reactions
37
4. 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
d) Thermal conductivity method
38
5. 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
c) Concentration of gas
39
6. 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
d) CO
40
7. Polarographic cells are not sensitive to which of the
following gases?
a) Carbon monoxide
b) Carbon dioxide
c) Nitrous oxide
d) Oxygen
a) Carbon monoxide
41
9. 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
b) False
42
8. 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
b) Cathode
43
1. Nitrogen dioxide can be detected with a paramagnetic
analyser.
a) True
b) False
a) True
44
2. 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
d) It is transparent in UV visible regions
45
10. Polarographic cells used for measuring the partial
pressure of oxygen are temperature-sensitive.
a) True
b) False
a) True
46
3. 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) Treating sample gas with pressurized oxygen
47
4. 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
b) Treating sample gas with ozone
48
8. 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
c) 1ppb to 1000ppb
49
5. 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
b) It is a slow process
50
9. 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
b) By placing NO in a magnetic field
51
10. 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
c) Liquid nitrogen cooled Ge-Au element
52
11. 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
c) Laser opto-acoustic spectroscopy
53
12. 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
d) Sulphanilic acid
54
13. 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) Collisional de-excitation
55
14. 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
b) False
56
2. 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
b) Solid state sensor
57
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
d) No interference from background gases
58
3. 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
d) No interference from background gases
59
4. 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
b) Lead Sulphide, brown colour
60
5. 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
c) Chemiluminescence method
61
6. 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) Resistance decreases with increase in H2S concentration
62
7. In the gold film sensor, the change in resistance is
proportional to the concentration of H2S.
a) True
b) False
a) True
63
8. 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
c) Oxidation-reduction reaction
64
1. Which of the following is not a detector used in mid
Infrared Spectrophotometer?
a) Thermopile
b) Thermistor
c) Pyroelectric cell
d) Golay cell
d) Golay cell
65
9. 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
d) Photo detector
66
3. 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) 2-10 Hz
67
4. 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
c) Hot-wire spiral
68
2. 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
c) Strong absorption of IR radiation by water
69
5. Vibration excitation occurs only if the sample has
hetero-atomic molecules.
a) True
b) False
a) True
70
6. 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
b) 2-50 Hz
71
7. 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
c) Variable capacitance
72
8. 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
d) Only one source is used
73
9. 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) PbSe
74
10. 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
c) Inert gases
75
11. 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
c) Sensitivity increases at longer wavelength
76
12. Luft detector cell which uses gas as detection
mechanism is not vibration sensitive.
a) True
b) False
b) False
77
13. 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
c) Narrow bandpass filter
78
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
d) Oxygen from a mixture of oxygen and nitrogen
79
5. Thermistors have positive temperature-coefficient of
resistance.
a) True
b) False
b) False
80
6. 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
b) Slow response
81
3. Which among the following elements has the highest
thermal conductivity?
a) Nitrogen
b) Oxygen
c) Hydrogen
d) Chlorine
c) Hydrogen
82
4. 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
b) Gold
83
2. 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
c) When all but one component have same thermal
conductivities
84
7. 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
b) By reducing the pressure of gas surrounding the
filaments
85
8. 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) Wheatstone bridge
86
9. Which of the following is generally used as indicators in
bridges in thermal conductivity analyzers?
a) Voltmeter
b) Ammeter
c) Galvanometer
d) Wattmeter
c) Galvanometer
87
2. 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
d) Room temperature and normal pressure
87
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
c) Linear
87
10. Changes in the composition of gas stream give rise to
changes in thermal conductivity of the gas stream.
a) True
b) False
a) True
88
3. Which of the following detectors are not used in
analyzers based on gas density?
a) Hot wire
b) Platinum filament
c) Thermistor
d) Thermometer
d) Thermometer
89
4. 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
d) When both the detectors are equally cooled
90
5. The use of thermistor eliminates the requirement for
amplification.
a) True
b) False
a) True
91
6. 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
d) Gas-density difference between both the detectors
92
7. 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) Wheatstone bridge
92
8. 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) It will cause a net downward flow
93
10. 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
c) 5 ml
93
9. When hot-wires are used as detectors amplification is
not required.
a) True
b) False
b) False
94
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
c) With sufficient electrical excitation and at suitable
pressures
95
3. 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) Purple
96
2. 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
d) By using a photospectrometer where a gas sample is analysed and detected with a photocell
97
4. 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
b) With the help of the needle valve
97
5. 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
c) 3 ml/min
98
6. 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
b) Water saturated mixture of nitrogen and oxygen
98
7. 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) It causes error
99
8. 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
b) By adjusting the needle valve
100
9. The voltage required for striking the discharge in the
presence of nitrogen is 1500V.
a) True
b) False
b) False
101
10. The light output from the discharge tube is interrupted
by means of a rotating slotted disc.
a) True
b) False
a) True
