X-Ray Spectrometers Flashcards
1
Q
- In X-ray spectrometers, the specimen or the sample is placed after which of the following components?
a) X-ray tube
b) Monochromator
c) Collimator
d) Detector
A
a) X-ray tube
2
Q
- Which of the following components are used to
generate X-rays?
a) Meyer tube
b) West tube
c) Anger tube
d) Coolidge tube
A
d) Coolidge tube
3
Q
- The cathode in the Coolidge tube is made of which of the following elements?
a) Quartz
b) Iron
c) Tungsten
d) Barium
A
c) Tungsten
3
Q
- The cathode in the Coolidge tube is kept in an inclined manner.
a) True
b) False
A
b) False
4
Q
- Using which of the following components is the
generated x-rays focussed upon the specimen?
a) X-ray tube
b) Monochromator
c) Collimator
d) Detector
A
c) Collimator
5
Q
- Which of the following is not a target metal used in the Coolidge tube?
a) Rhodium
b) Cobalt
c) Gold
d) Silver
A
c) Gold
6
Q
- When compared to filters, monochromators provide
much signal to noise ratio.
a) True
b) False
A
a) True
6
Q
- When x-rays emitted from molybdenum are allowed to pass through a zirconium filter, which of the following occurs?
a) It absorbs radiation of shorter wavelength
b) It absorbs radiation of longer wavelength
c) It allows radiation of shorter wavelength to pass
through
d) It allows radiation in a particular band to pass through
A
b) It absorbs radiation of longer wavelength
7
Q
- The x-rays generated come out of the Coolidge tube through which of the following?
a) Beryllium window
b) Tungsten window
c) Collimator
d) Target material
A
a) Beryllium window
7
Q
- How can the resolution of the collimator be increased?
a) By reducing the separation between the metal plates of the collimator
b) By increasing the separation between the metal plates of the collimator
c) By increasing the number of metal plates
d) By decreasing the number of metal plates
A
a) By reducing the separation between the metal plates of the collimator
8
Q
- Which of the following crystals are not suited for x-ray grating?
a) Topaz
b) Lithium fluoride
c) Calcium fluoride
d) Sodium fluoride
A
d) Sodium fluoride
9
Q
- X-ray diffractometers provide ____________
information about the compounds present in a solid
sample.
a) Quantitative
b) Qualitative
c) Quantitative and qualitative
d) Either quantitative or qualitative
A
c) Quantitative and qualitative
10
Q
- X-ray diffractometers are not used to identify the
physical properties of which of the following?
a) Metals
b) Liquids
c) Polymeric materials
d) Solids
A
c) Polymeric materials
11
Q
- Using the powder method of diffractometers, which of the following can be determined?
a) Percentage of K+
b) Percentage of Na+ and Cl-
c) Percentage of KBr and NaCl
d) Percentage of Br-
A
c) Percentage of KBr and NaCl
12
Q
- Which of the following is the most common instrument for photographic recording of diffraction patterns?
a) Debye-Scherrer powder camera
b) Gamma camera
c) Geiger tube
d) Scintillation counter
A
a) Debye-Scherrer powder camera
12
Q
- In powder method, the powder sample is contained in which of the following?
a) Thin walled glass capillary tubes
b) Thin walled test tube
c) Thin walled curvettes
d) Thin walled flask
A
a) Thin walled glass capillary tubes
13
Q
- In Diffractometer, the identification of a component of the sample from its powder diffraction pattern is based upon the _________ of lines and their relative
___________
a) Number, length
b) Number, intensity
c) Position, length
d) Position, intensity
A
d) Position, intensity
13
Q
- With the help of which of the following equations is the distance calculated from a known wavelength of the source and measured angle?
a) Coolidge equation
b) Bragg’s equation
c) Debye equation
d) Scherrer equation
A
b) Bragg’s equation
14
Q
- When certain geometric requirements are met, X-rays scattered from a crystalline solid can constructively interfere with each other and produce a diffracted beam.
a) True
b) False
A
a) True
15
Q
- In Diffractometers, the intensities of the diffraction
peaks of a given compound in a mixture are proportional to the fraction of the material in the mixture.
a) Number
b) False
A
a) Number
15
Q
- Diffractometers are similar to which of the following?
a) Optical grating spectrometer
b) Prism spectrometer
c) Photo multiplier
d) Photovoltaic cell
A
a) Optical grating spectrometer
16
Q
- In Diffractometers, line intensities depend on ______ and kind of atomic reflection centres in each set of plates.
a) Number
b) Position
c) Length
d) Distance between lines
A
a) Number
17
Q
- In powder diffractometer, the sharpness of the lines is
greatly determined by which of the following?
a) Quality of the sample, size of the slit
b) Quality of the slit, size of the sample
c) Thickness of the slit, amount of the sample
d) Number of slits, composition of the sample
A
b) Quality of the slit, size of the sample
18
Q
- Absorption meter is __________ and ____________ of
the chemical state of the element concerned.
a) Non-destructive, independent
b) Destructive, independent
c) Non-destructive, dependent
d) Destructive, dependent
A
a) Non-destructive, independent
19
Q
- X-ray absorption meters have which of the following
major disadvantages?
a) Low accuracy
b) Low range
c) Low sensitivity
d) It is destructive
A
c) Low sensitivity
20
Q
- The applications of X-ray absorption meters are limited when compared with X-ray emission procedures.
a) True
b) False
A
a) True
21
Q
- In absorption meter, which of the following is placed
between the cell and the X-ray tube?
a) Collimator
b) Filter
c) Chopper
d) Attenuator
A
c) Chopper
22
Q
- In absorption meter, the two halves of the X-ray beam are allowed to fall on which of the following components?
a) Collimator
b) Filter
c) Photomultiplier tube
d) Attenuator
A
c) Photomultiplier tube
22
Q
- In absorption meter, which of the following is placed
between the chopper and the reference cell?
a) Collimator
b) Filter
c) Photomultiplier tube
d) Attenuator
A
d) Attenuator
23
Q
- The photomultiplier tube used is absorption meter is coated with which of the following materials?
a) Sodium
b) Potassium
c) Phosphorous
d) Chlorine
A
c) Phosphorous
24
Q
- In absorption meter, which of the following is adjusted until the absorption of two X-ray beams are brought into balance?
a) Collimator
b) Filter
c) Photomultiplier tube
d) Attenuator
A
d) Attenuator
25
Q
- In absorption meter, the change in thickness of
aluminium required for different samples is a function of the difference in which of the following parameters?
a) Amount
b) Concentration
c) Colour
d) Composition
A
d) Composition
25
Q
- Absorption meters cannot be used to detect broken bones.
a) True
b) False
A
b) False
26
Q
- If the absorption of electromagnetic radiation by matter results in the emission of radiation of the same or longer wavelengths for a long or a short time, the phenomenon is termed as which of the following?
a) Luminescence
b) Fluorescence
c) Phosphorescence
d) Spontaneous emission
A
a) Luminescence
27
Q
- If the absorption of electromagnetic radiation by matter results in the emission of radiation of the same or longer wavelengths for a short time, the phenomenon is termed as which of the following?
a) Luminescence
b) Fluorescence
c) Phosphorescence
d) Spontaneous emission
A
b) Fluorescence
28
Q
- If the absorption of electromagnetic radiation by matter results in the emission of radiation of the same or longer wavelengths for a long time, the phenomenon is termed as which of the following?
a) Luminescence
b) Fluorescence
c) Phosphorescence
d) Spontaneous emission
A
c) Phosphorescence
29
Q
- Prompt emission of X-ray by an atom ionised by a higher energy X-ray is a type of which of the following
phenomena?
a) Luminescence
b) Fluorescence
c) Phosphorescence
d) Spontaneous emission
A
b) Fluorescence
30
Q
- The measurement of intensity of fluorescent X-rays
provide a simple and ____________ way of
_____________ analysis.
a) Destructive, quantitative
b) Non-destructive, quantitative
c) Destructive, qualitative
d) Non-destructive, qualitative
A
b) Non-destructive, quantitative
31
Q
- The energy of the emitted X-rays depends upon the
_________ of the atom and their intensity depends upon
the __________
a) Atomic number, amount of sample
b) Mass number, amount of sample
c) Mass number, concentration of atoms
d) Atomic number, concentration of atoms
A
d) Atomic number, concentration of atoms
32
Q
- Which of the following is Mosely’s equation if ‘C’ is the speed of light, ‘a’ is proportionality constant, ‘σ’ is a
constant which depends on electronic transition series, ‘Z’ is the atomic number and ‘λ’ is the wavelength?
a) Cλ= a(Z-σ)2
b) C/λ= a(Z-σ)2
c) C(Z-σ)2= aλ
d) C(Z-σ)2= a/λ
A
b) C/λ= a(Z-σ)2
33
Q
- The problem of spectral interference is not severe in Xray spectroscopy.
a) True
b) False
A
a) True
34
Q
- In X-ray fluorescence spectrometer, the relationship
between the excitation intensity and the intensity of
fluorescence does not depend on which of the following?
a) Spectrum of the incident radiation
b) Angle of radiance
c) Molecular weight
d) Incident angle
A
d) Incident angle
35
Q
- Fluorescent X-ray spectrometers would require only moderate-intensity X-ray tubes.
a) True
b) False
A
b) False
36
Q
- Which of the following components of the X-ray
fluorescent spectrometer induces fluorescent radiation?
a) Excitation source
b) Energy analyser
c) X-ray spectrometer
d) Detection System
A
a) Excitation source
37
Q
- Why is a mono-energetic radiation source required in Xray fluorescent spectrometer?
a) To provide good sensitivity
b) To provide high accuracy
c) To provide a proper range
d) To reduce unwanted background
A
d) To reduce unwanted background
38
Q
- Which of the following does not make the X-ray tube
nearly monochromatic?
a) Transmission-anode X-ray tube
b) Secondary fluorescence target
c) Slit
d) Filters
A
c) Slit
39
Q
- Which of the following components make use of a thin metal foil to isolate a nearly mono-energetic excitation beam?
a) Transmission-anode X-ray tube
b) Secondary fluorescence target
c) Slit
d) Filters
A
d) Filters
40
Q
- Energy dispersive system uses which of the following detectors?
a) Optical detector
b) Semiconductor detector
c) Thermistor
d) Bolometer
A
b) Semiconductor detector
41
Q
- In Energy dispersive system, the energy level and the number of pulses is related to which of the following?
a) Amount of sample, element involved
b) Element involved, concentration of the element
c) Concentration of the element, element involved
d) Number of atoms, amount of sample
A
b) Element involved, concentration of the element
42
Q
- The analysis of X-ray beam by diffraction is similar to
spectrum analysis carried out with a diffraction grating.
a) True
b) False
A
a) True
43
Q
- The crystal used as X-ray grating has _______
dimensional lattice arrays.
a) One
b) Two
c) Three
d) Four
A
c) Three
44
Q
- Which of the following can be done to avoid loss of
intensities of X-rays due to the absorption of long
wavelength X-rays?
a) Apparatus must be contained in a chamber
b) Air in the chamber must be replaced by helium
c) Inert gas atmosphere must be provided
d) Proper slits must be used
A
b) Air in the chamber must be replaced by helium
45
Q
- In curved crystal arrangement, angular velocity of the crystal is twice that of the detector.
a) True
b) False
A
b) False
46
Q
- Which of the following is the disadvantage of silicon semiconductor detector?
a) Low stable
b) Can be operated only at low temperatures
c) Have low count-rate
d) Low resolution
A
b) Can be operated only at low temperatures
47
Q
- In total reflection X-ray fluorescence spectrometer, the specimen is excited by the primary X-ray beam at a grazing angle _______ the critical angle.
a) Greater than
b) Less than
c) Equal to
d) Which is a complement of
A
b) Less than
48
Q
- The x-ray beam produced by the primary x-ray tube
passes through which of the following components to
produce the incident radiation?
a) Detector
b) Slit-collimator arrangement
c) Sample reflector
d) Monochromator
A
b) Slit-collimator arrangement
49
Q
- The suppression of high energy bremsstrahlung
radiation improves which of the following?
a) Signal to background ratio
b) Accuracy
c) Sensitivity
d) Coherence
A
b) Accuracy
49
Q
- Which of the following crystals are polished to act as the cut-off reflector?
a) Quartz
b) Beryllium
c) Silicon
d) Lithium
A
c) Silicon
50
Q
- Which of the following components are used as the
sample carrier?
a) Curvette
b) Flask
c) Capillary tube
d) Float glass
A
d) Float glass
50
Q
- Which of the following devices are used as a detector?
a) Thermistor
b) Optical detector
c) Solid state detector
d) Golay cell
A
c) Solid state detector
51
Q
- Which of the following happens when a large solid angle is intercepted as the detector is placed close to the sample?
a) Maximum efficiency increases
b) Maximum efficiency decreases
c) Efficiency is not affected
d) Process response becomes fast
A
a) Maximum efficiency increases
52
Q
- The major problem associated with sample preparation is which of the following?
a) Preparing sample in the right quantity
b) Choosing sample holders
c) Matrix effects
d) Reflection by holders
A
c) Matrix effects
52
Q
- To monitor the primary beam, which of the following is used?
a) Scintillation counter
b) GM counter
c) Gamma counter
d) Proportional counter
A
b) GM counter
53
Q
- Computer-controlled corrective iteration is the only
reliable method of matrix effects correction.
a) True
b) False
A
a) True
54
Q
- In computer-controlled corrective iteration method, which of the following is used to estimate absorption corrections?
a) Test tube
a) Initial raw intensity data
b) Elemental composition
c) Amount of sample
d) Amount of radiation
A
a) Test tube
55
Q
- Total reflection X-ray fluorescence spectrometer is
attractive for elements which lack reliable wet chemical methods.
a) True
b) False
A
a) True
56
Q
- Which of the following is not a type of optics employed in electron probe microanalyser?
a) Electron optics
b) Light optics
c) X-ray optics
d) Gamma optics
A
d) Gamma optics
57
Q
- The electron optics consists of an electron gun followed by which of the following components?
a) Collimator
b) Slit
c) Amplifier
d) Electron beam probe
A
d) Electron beam probe
58
Q
- The specimen is mounted inside which of the following components?
b) Glass capillary tube
c) Vacuum column
d) Curvette
A
c) Vacuum column
58
Q
- The electrons are accelerated by voltages in which of the following ranges?
a) 5 and 50kV
b) 50 and 500kV
c) 500 and 5000kV
d) 25 and 250kV
A
a) 5 and 50kV
59
Q
- Micro probe analyser cannot be used on
inhomogeneous material.
a) True
b) False
A
a) True
59
Q
- Electron probe microanalyser is a method of destructive elemental analysis.
a) True
b) False
A
a) True
60
Q
- Which of the following is the effective resolution limit in electron probe microanalyser?
a) 1mm
b) 10mm
c) 100mm
d) 1000mm
A
60
Q
- The alternative method using laser does not analyse vapours by which of the following methods?
a) Mass spectrometer
b) Optical emission
c) Absorption photometry
d) X-ray photometry
A
d) X-ray photometry
60
Q
- Which of the following is the limit of detectability of
electron microprobe analyser?
a) 10-14 g
b) 10-140 g
c) 10-7 g
d) 10-70 g
A
a) 10-14 g
61
Q
- X-ray emission must be analysed against a background of _______ radiation.
a) Blue
b) Yellow
c) White
d) Green
A
c) White
