Absorption Instrumentation and Block Diagram Representation Flashcards
1
Q
- Which of the following detectors does not require a
battery and is also known as barrier layer cell?
a) Photomultiplier tube
b) Photovoltaic cell
c) Photoemissive tubes
d) Photo reflector
A
b) Photovoltaic cell
2
Q
- Which of the following detectors is used to detect light
intensities which are very weak?
a) Photomultiplier tube
b) Photovoltaic cell
c) Photoemissive tubes
d) Photo reflector
A
a) Photomultiplier tube
3
Q
- How is Tungsten Halogen lamp differs from normal
Tungsten filament lamp used in absorption spectroscopy?
a) It has a tungsten filament and is filled with inert gas
b) Iodine is added to normal filling gas
c) Iodine is coated on tungsten filament
d) Iodine is added to inert gas
A
b) Iodine is added to normal filling gas
4
Q
- Instead of glass filters, why gelatin filters could not be
used for a long period while both are Absorption filters?
a) Gelatin tends to evaporate and hence they deteriorate
b) Gelatin is affected by humidity in the environment
c) They deteriorate due to absorption of heat leading to
changes in gelatin
d) Gelation is affected by temperature in the environment
A
c) They deteriorate due to absorption of heat leading to
changes in gelatin
5
Q
- How does continuous wedge filter differ from normal
interference filter used in absorption spectroscopy?
a) It permits continuous selection of different wavelength
b) It allows a narrow band of wavelengths to pass
c) It has two semi-transparent layers of silver
A
a) It permits continuous selection of different wavelength
6
Q
- Which of the following could be used as the layer of
dielectric in interference filters used in Absorption
Spectroscopy?
a) Graphite
b) MgF2
c) Fe
d) AgNO3
A
b) MgF2
7
Q
- How can stability of radiation be achieved in
incandescent or discharge source used in Absorption
Spectroscopy?
a) Using filters
b) Using monochromators
c) Using slits
d) By controlling the source voltage
A
d) By controlling the source voltage
8
Q
- To tolerate high operating temperatures, which of the
following has to be done in incandescent or tungsten
filament lamps?
a) Alloys must be used
b) Nitrogen be used instead of inert gas
c) Envelope is fabricated with quartz
d) Envelope is fabricated with copper
A
c) Envelope is fabricated with quartz
9
Q
- Which of the following is not a reason for laser not
being generally used as a source of radiation for UV,
Visible Spectroscopy?
a) High cost
b) Limited range of wavelength
c) Less intensity
d) Complex to work with
A
c) Less intensity
10
Q
- Which of the following statements is false about single
beam absorption instruments?
a) Tungsten bulb is used as a source
b) Beam splitter is used to get parallel beam
c) Test tube is used as sample holder
d) Photovoltaic cell as detector
A
b) Beam splitter is used to get parallel beam
11
Q
- Which of the following statement is false about double
beam absorption instruments?
a) It is similar to single beam instruments except two
beams are present
b) Tungsten bulb is used as a source
c) Reference beam must have a higher intensity than
sample beam
d) Both the beams after they pass through respective
samples are compared
A
c) Reference beam must have a higher intensity than
sample beam
12
Q
- Which of the following is not an application of
colorimeter?
a) Paints
b) Inks
c) Cosmetics
d) Composition detection
A
d) Composition detection
13
Q
- In photometers, the readings of the specimen are
initially obtained in the form of which of the following
parameters?
a) Transmittance
b) Absorption
c) Wavelengths
d) Volume
A
a) Transmittance
14
Q
- Colorimeters are used in applications where great
accuracy is required.
a) True
b) False
A
b) False
15
Q
- Which of the following is the purpose of balance
indicator in double beam photometer or colorimeter?
a) Selects a particular wavelength
b) Splits the wavelength selected into two equal beams
c) Detects and indicates the amount of light falling on it
d) Indicates the difference between the output of two
photometers
A
d) Indicates the difference between the output of two
photometers
15
Q
- Colorimeters are used to determine the concentration
of solutions.
a) True
b) False
A
a) True
16
Q
- Which of the following is the purpose of the beam
splitter in double beam photometer or colorimeter?
a) Splits beam into two equal intensity beams
b) Splits beam in such a way that sample beam has higher
intensity
c) Splits beam in such a way that a reference beam has
higher intensity
d) Merge two equal intensity beams into single beam
A
a) Splits beam into two equal intensity beams
17
Q
- Which of the following is a source used in
spectroscopy?
a) LASER
b) Tube light
c) Sodium vapour lamp
d) Tungsten lamp
A
d) Tungsten lamp
18
Q
- Which of the following is the wave number of near
infrared spectrometer?
a) 4000 – 200 cm^-1
b) 200 – 10 cm^-1
c) 12500 – 4000 cm^-1
d) 50 – 1000 cm^-1
A
c) 12500 – 4000 cm^-1
18
Q
- Which of the following is not a source used in Mid
Infrared Spectrophotometer?
a) Nernst glower
b) High pressure mercury arc lamp
c) Globar
d) Nichrome wire
A
b) High pressure mercury arc lamp
19
Q
- Which of the following options are correct in terms of
wavelength for the different types of IR spectrometer?
a) Near IR: 0.8 – 2.5 mm
b) Mid IR: 0.8 – 2.5 mm
c) Far IR: 2.5 – 50 mm
d) Mid IR: 50 – 100 mm
A
a) Near IR: 0.8 – 2.5 mm
20
Q
- What is the composition of Globar rod which is used as
a source in Mid IR spectroscopy?
a) Silicon carbide
b) Silver chloride
c) Silicon dioxide
d) Silver carbide
A
a) Silicon carbide
21
Q
- Which of the following is not a composition of Nernst
glower or Nernst filament?
a) Oxides of Zirconium
b) Oxides of Barium
c) Oxides of Yitrium
d) Oxides of Thorium
A
b) Oxides of Barium
22
Q
- Bolometer, a type of detector, is also known as
___________
a) Resistance temperature detector (RTD)
b) Thermistor
c) Thermocouple
d) Golay cell
A
b) Thermistor
23
Q
- Which of the following is not used as pyroelectric
material used in pyroelectric transducers in Infrared
spectroscopy?
a) Triglycine Sulphate
b) Deutrated Triglycine Sulphate
c) Some Polymers
d) Tetraglycine sulphate
A
d) Tetraglycine sulphate
24
Q
- Which of the following is not a technique for preparing
solid samples in IR spectroscopy?
a) Solids run in solution
b) Mull technique
c) Solid films
d) Thin films
A
d) Thin films
25
Q
- Which of the following is the principle of Golay cell
which is used as a detector in IR spectroscopy?
a) Expansion of gas upon heating
b) Increase in resistance due to an increase in temperature
and vice versa
c) Temperature difference gives rise to a potential
difference in the material
d) Decrease in resistance due to an increase in
temperature
A
a) Expansion of gas upon heating
26
Q
- In a solid sample treatment technique, the finely
ground solid sample is mixed with mineral oil to make a
thick paste which is then spread between IR transmitting
windows. What is the name of this solid sample treatment
technique?
a) Pressed pellet
b) Mull technique
c) Solid films
d) Solids run in solution
A
b) Mull technique
27
Q
- Which of the following is not true about Fourier
Transform Infrared (FTIR) spectrometer?
a) It is of non-dispersive type
b) It is useful where repetitive analysis is required
c) Size has been reduced over the years
d) Size has increased over the years
A
d) Size has increased over the years
28
Q
- In the most widely used beam splitter, a thin film of
________ is sandwiched between two plates of low
refractive index solid. Fill the blank with a suitable option.
a) Mylar
b) Silicon carbide
c) Ferrous oxide
d) Silver chloride
A
a) Mylar
29
Q
- Which of the following is not the function of the drive
mechanism in Fourier Transform Infrared
Spectrophotometer?
a) Movement of mirror to obtain a satisfactory
interferogram
b) Acquire a good interferogram pattern
c) Allow 50% of the beam to pass
d) Keep the speed of the moving mirror constant
A
c) Allow 50% of the beam to pass
30
Q
- Only pyroelectric transducer or pyroelectric crystals are
used as detectors in Fourier Transform Infrared
Spectrophotometer (FTIR). What is the main reason for
other types of thermal detectors are not being used in
FTIR spectrophotometer?
a) Less accuracy
b) Slower response
c) Less precision
d) Less sensitivity
A
b) Slower response
31
Q
- Which of the following has to be computed to
determine transmittance and absorbance at various
frequencies?
a) Ratio of signal and noise
b) Ratio of sample and reference spectra
c) Sample spectra
d) Reference spectra
A
b) Ratio of sample and reference spectra
31
Q
- Which of the following is not the advantage of Fourier
Transform Spectrometers?
a) Signal to noise ratio is high
b) Information could be obtained on all frequencies
c) Retrieval of data is possible
d) Easy to maintain
A
d) Easy to maintain
32
Q
- Computer accepts analog signals directly.
a) True
b) False
A
b) False
33
Q
- Which of the following is the reference that is generally
used in FTIR interferometer?
a) Air
b) NaCl solution
c) Alcohol
d) Base solution
A
a) Air
34
Q
- In Michelson Interferometer, if the reflected and
transmitted beams are in phase at the beam splitter, then
maximum intensity will reach the detector.
a) True
b) False
A
a) True
35
Q
- In Michelson’s interferometer, the __________ of the
detector output will depend upon the intensity of
incoming radiation.
a) Velocity
b) Frequency
c) Amplitude
d) Phase
A
c) Amplitude
35
Q
In Michelson’s interferometer, the frequency of the detector output can be determined by translating the
_________ of movable mirror and the ___________ of
monochromatic radiation.
a) Velocity, wavelength
b) Thickness, intensity
c) Length, velocity
d) Angle, intensity
A
a) Velocity, wavelength
36
Q
- Why is the computer necessary in Fourier Transform
Spectrometer?
a) To display the detector output
b) To process the detector output
c) To determine the amplitude
d) To determine the frequency
A
b) To process the detector output
37
Q
- Which of the following is the principle of Atomic
Absorption Spectroscopy?
a) Radiation is absorbed by non-excited atoms in vapour
state and are excited to higher states
b) Medium absorbs radiation and transmitted radiation is
measured
c) Colour is measured
d) Colour is simply observed
A
a) Radiation is absorbed by non-excited atoms in vapour
state and are excited to higher states
38
Q
- In Atomic Absorption Spectroscopy, which of the
following is the generally used radiation source?
a) Tungsten lamp
b) Xenon mercury arc lamp
c) Hydrogen or deuterium discharge lamp
d) Hollow cathode lamp
A
d) Hollow cathode lamp
39
Q
- How can the intensity of radiation be increased in
Hollow cathode lamp?
a) Addition of non-conductive protective shield of mica
b) Addition of nitrogen to neon or argon in the lamp
c) Increasing the pressure of the filling gas
d) Changing the metal of the anode
A
a) Addition of non-conductive protective shield of mica
39
Q
- Which of the following is the function of the chopper in
Atomic Absorption Spectroscopy?
a) To split the beam into two
b) To break the steady light into a pulsating light
c) To filter unwanted components
d) To reduce the sample into atomic state
A
b) To break the steady light into a pulsating light
40
Q
- In Atomic Absorption Spectroscopy, with what material
is the cathode in Hollow cathode lamp constructed?
a) Tungsten
b) Quartz
c) Element to be investigated
d) Aluminium
A
c) Element to be investigated
41
Q
- Which of the following is the function of the Flame or
Emission system in Atomic Absorption Spectroscopy?
a) To split the beam into two
b) To break the steady light into pulsating light
c) To filter unwanted components
d) To reduce the sample into atomic state
A
d) To reduce the sample into atomic state
42
Q
- Atomic absorption spectroscopy is also called as
Absorption Flame Photometry.
a) True
b) False
A
a) True
43
Q
- Which of the following is not a component of the
emission system in Flame photometer?
a) Burner
b) Atomiser
c) Fuel gases and their regulation
d) Chopper
A
d) Chopper
44
Q
- Which of the following is not a fuel used in flame
photometry?
a) Acetylene
b) Propane
c) Hydrogen
d) Camphor oil
A
d) Camphor oil
44
Q
- Which of the following is the function of the atomiser in
the emission system of Atomic Absorption Spectroscopy?
a) To split the beam into two
b) To break the steady light into pulsating light
c) To break large mass of liquid into small drops
d) To reduce the sample into atomic state
A
c) To break large mass of liquid into small drops
45
Q
- Which of the following is not the requirement of a
good flame in flame photometer?
a) Liquid sample must be evaporated to form solid residue
b) Solid residue must decompose to form atoms
c) Atoms must be produced such that they have the ability
to get excited to higher states
d) Atoms must be produced such that they are in stable
state
A
d) Atoms must be produced such that they are in stable
state
46
Q
- Atomic Absorption Spectroscopy is used for the
analysis of metals.
a) True
b) False
A
a) True
47
Q
- Which of the following options explains the process of
‘sputtering’ that occurs in Hollow Cathode Lamp?
a) Positive ions collide with cathode surface and metal
atoms from cathode are ejected
b) Negative ions collide with cathode surface and metal
atoms from anode are ejected
c) Positive ions collide with negative ions and metal atoms
from anode are ejected
d) Positive ions collide with negative ions and photons are
ejected
A
a) Positive ions collide with cathode surface and metal
atoms from cathode are ejected
48
Q
- At what pressure should the gases in the sealed tube
be maintained in the Hollow cathode lamp?
a) 1 to 5 torr
b) 20 to 30 torr
c) 40 to 50 torr
d) 50 to 55 torr
A
a) 1 to 5 torr
49
Q
- The function of pressure regulators in the emission
system of flame photometer is to have a steady flame
which is free from flickers.
a) True
b) False
A
a) True
50
Q
- In Total consumption burner, only samples of particular
droplet size will enter the burner.
a) True
b) False
A
b) False
51
Q
- Which of the following is the principle of Flame emission
photometers?
a) Radiation is absorbed by non-excited atoms in vapour
state and are excited to higher states
b) Medium absorbs radiation and transmitted radiation is
measured
c) Colour and wavelength of the flame is measured
d) Only wavelength of the flame is measured
A
c) Colour and wavelength of the flame is measured
52
Q
- In Flame emission photometers, the measurement of
_____________ is used for qualitative analysis.
a) Colour
b) Intensity
c) Velocity
d) Frequency
A
a) Colour
53
Q
- In Flame emission photometers, the measurement of
_____________ is used for quantitative analysis.
a) Colour
b) Intensity
c) Velocity
d) Frequency
A
b) Intensity
54
Q
- Which of the following is not an advantage of Laminar
flow burner used in Flame photometry?
a) Noiseless
b) Stable flame for analysis
c) Efficient atomization of sample
d) Sample containing two or more solvents can be burned
efficiently
A
d) Sample containing two or more solvents can be burned
efficiently
55
Q
- Laminar flow burner used in Flame photometers is also
known as ____________
a) Turbulent burner
b) Premix burner
c) Total consumption burner
d) Nozzle mix burner
A
b) Premix burner
56
Q
- Which of the following is the advantage of prism
monochromators?
a) Dispersion is non-overlapping
b) Dispersion occurs in non-linear manner
c) Dispersion is overlapping
d) Dispersion occurs in a linear manner
A
a) Dispersion is non-overlapping
57
Q
- Which of the following is the advantage of grating
monochromators?
a) Dispersion is non-overlapping
b) Dispersion occurs in non-linear manner
c) Dispersion is overlapping
d) Dispersion occurs in a linear manner
A
d) Dispersion occurs in a linear manner
58
Q
- Which of the following is not a detector used in Flame
emission photometers?
a) Photronic cell
b) Photovoltaic cell
c) Photoemissive tube
d) Chromatogram
A
d) Chromatogram
59
Q
- Phototubes are more sensitive than photovoltaic cells.
a) True
b) False
A
a) True
60
Q
- Which of the following is not an application of Flame
emission photometers?
a) Analysis of biological fluids
b) Determination of sodium, potassium in soil
c) Determination of metals such as Mn, Cu
d) Analysis of complex mixtures
A
d) Analysis of complex mixtures
61
Q
- Which of the following is not an advantage of a
photovoltaic cell which is used as a detector in Flame
emission photometers?
a) Portable
b) No external supply
c) Robust in construction
d) Does not show fatigue
A
d) Does not show fatigue
