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Multiple choice question for engineering

Set 1

1. Which of the following is the distance that the solute moves while undergoing one partition?
a) Retention distance
b) Distribution constant
c) Plate height
d) Column packing length

View Answer

Answer: c [Reason:] Plate height is the distance that the solute moves while undergoing one partition. It is expressed in length.

2. Which of the following conditions will cause the efficiency of the column to increase?
a) Plate number becomes greater, plate height becomes smaller
b) Plate number becomes smaller, plate height becomes smaller
c) Plate number becomes greater, plate height becomes larger
d) Plate number becomes greater, plate height becomes larger

View Answer

Answer: a [Reason:] The efficiency of the column increases when the plate number becomes greater and the plate height becomes smaller. Column efficiency greatly depends on plate height and plate number.

3. Which of the following is the expression for Eddy diffusion in the column, if ‘γ’ represents obstruction factor, ‘dp’ represents particle diameter, ‘DM’ represents Solute diffusion co-efficient and ‘λ’ represents function for packing uniformity?
a) λ dM
b) 2 γ DM
c) DM γ
d) λ/dM

View Answer

Answer: a [Reason:] Eddy diffusion is given as, A = λ dp. It is also called multipath term.

4. Which of the following is the expression for longitudinal diffusion in the column, if ‘γ’ represents obstruction factor, ‘dM’ represents particle diameter, ‘DM’ represents Solute diffusion co-efficient and ‘λ’ represents function for packing uniformity?
a) λ dM
b) 2 γ DM
c) DM γ
d) λ/dM

View Answer

Answer: b [Reason:] Longitudinal diffusion is given as, B = 2 γ DM.It is also called axial diffusion.

5. In gas-liquid chromatography, when films are used in the interior of capillary column, then what is the value of Eddy diffusion?
a) Greater than 1
b) Less than 1
c) Zero
d) Less than zero

View Answer

Answer: c [Reason:] In gas-liquid chromatography, when films are used in the interior of capillary column the value of Eddy diffusion (A) is zero. To minimize A, diameter of packing should be small and uniform.

6. For an unpacked coated capillary column, the obstruction factor takes which of the following values?
a) 0
b) 0.6
c) 1
d) 1.6

View Answer

Answer: c [Reason:] For an unpacked coated capillary column, the value of obstruction factor is 1. For a packed column, the value is 0.6.

7. Base line resolution is achieved when degree of resolution/separation is ______
a) 1
b) 0
c) 0.5
d) 1.5

View Answer

Answer: d [Reason:] Base line resolution is achieved when degree of resolution/separation is 1.5. The baseline bandwidths of adjacent bands are almost constant.

8. Which of the following equations give the expression for plate number, N when ‘tR’ is the adjusted retention time and ‘Wb’ is the width at the base of the peak which is equal to 4 standard deviations.
a) 16 tR2/Wb
b) 4 tR2/Wb
c) (4tR/Wb)2
d) 4 (tR/Wb)2

View Answer

Answer: c [Reason:] The expression for plate number, N is given as N = (4tR/Wb)2. It is a dimensionless quantity.

9. It is more difficult to measure the width at half peak height than the base width in the detector output.
a) True
b) False

View Answer

Answer: b [Reason:] The width at half peak height is easier to measure than the base width. Hence, the plate number is calculated at peak height.

10. The solute, while moving in the column is always in equilibrium with both the stationary phase and the mobile phase.
a) True
b) False

View Answer

Answer: a [Reason:] The solute, while moving in the column is always in equilibrium with both the stationary phase and the mobile phase. But, the two phases will never be in equilibrium with each other.

Set 2

1. NMR spectroscopy is used for determining structure in which of the following materials?
a) Radioactive materials
b) Insoluble chemical compounds
c) Liquids
d) Gases

View Answer

Answer: c [Reason:] NMR spectroscopy is used for determining structure in liquids. It is also used for determining the structure in soluble chemical compounds.

2. NMR is the study of absorption of __________ by nuclei in a magnetic field?
a) Radioactive radiation
b) IR radiation
c) Radio frequency radiation
d) Microwaves

View Answer

Answer: c [Reason:] NMR is the study of absorption of radio frequency radiation by nuclei in a magnetic field. For a particular nucleus an NMR absorption spectrum may consist of one to several groups of absorption lines.

3. NMR spectrometer provides ____________ and _____________ method of determining structure
in soluble chemical compounds.
a) Accurate, destructive
b) Accurate, non-destructive
c) Inaccurate, destructive
d) Inaccurate, non-destructive

View Answer

Answer: b [Reason:] NMR spectrometer provides accurate and non-destructive method of determining structure in soluble chemical compounds. For a particular nucleus an NMR absorption spectrum may consist of one to several groups of absorption lines.

4. NMR spectroscopy indicates the chemical nature of the __________ and spatial positions of
_______
a) Electrons, Protons
b) Neutrons, electrons
c) Nuclei, electrons
d) Nuclei, neighbouring nuclei

View Answer

Answer: d [Reason:] NMR spectroscopy indicates the chemical nature of the nuclei and spatial positions of neighbouring nuclei. It is one of most powerful techniques for chemical analysis.

5. In NMR spectroscopy, the spinning nuclei in strong magnetic field must be irradiated by which of the following?
a) Perpendicular and stronger field
b) Perpendicular and weaker field
c) Parallel and stronger field
d) Parallel and weaker field

View Answer

Answer: b [Reason:] In NMR spectroscopy, the spinning nuclei in strong magnetic field must be irradiated by a weaker field which is perpendicular to it. This permits the identification of atomic configurations in molecules.

6. Interaction between matter and electromagnetic radiation can be observed by subjecting a substance to magnetic fields in which of the following manner?
a) Both fields should be stationary
b) Both fields should be varying
c) One field should be stationary and the other should be varying
d) It must be subjected to only one field

View Answer

Answer: c [Reason:] Interaction between matter and electromagnetic radiation can be observed by subjecting a substance to two magnetic fields. One magnetic field must be stationary and the other field must be varying at some radio frequency.

7. When energy is absorbed by the sample, the absorption can be observed as a change in signal developed by which of the following components?
a) Amplifier
b) Photodetector
c) GM counter
d) Radiofrequency detector

View Answer

Answer: d [Reason:] When energy is absorbed by the sample, the absorption can be observed as a change in signal developed by radiofrequency detector. It is then given to an amplifier.

8. Which of the following are considered to be the lowest form of Electromagnetic radiation?
a) IR radiation
b) Micro waves
c) UV radiation
d) Radio waves

View Answer

Answer: d [Reason:] Radio waves are considered to be the lowest form of Electromagnetic radiation. NMR uses radio frequency radiation for detection of structure of substances.

9. The amount of energy available in radio frequency radiation is sufficient for which of the following?
a) Excite an atom
b) Vibrate an atom
c) Vibrate a molecule
d) Affect the nuclear spin of an atom

View Answer

Answer: d [Reason:] The amount of energy available in radio frequency radiation is sufficient for affecting the nuclear spin of an atom. It constitute the most fundamental part of spectroscopy.

10. Nuclei having either the number of protons or neutrons as odd have _______ spin.
a) Integral spin
b) Half integral spin
c) Zero spin
d) Positive spin

View Answer

Answer: b [Reason:] Nuclei having either the number of protons or neutrons as odd have half-integral spin. Examples are H1 and B11.

11. If the number of protons or neutrons is even the spin of the nucleus will be which of the following?
a) Integral spin
b) Half integral spin
c) Zero spin
d) Positive spin

View Answer

Answer: c [Reason:] If the number of protons or neutrons is even the spin of the nucleus will be zero. Examples are C12 and O16.

12. The difference between the field necessary for resonance in the sample and in some arbitrary
chosen compound is which of the following?
a) Field shift
b) Matrix effects
c) Chemical shift
d) Resonance shift

View Answer

Answer: c [Reason:] The difference between the field necessary for resonance in the sample and in some arbitrary chosen compound is called as chemical shift. Chemical shift is expressed in parts per million.

13. Chemical shift allows a chemist to obtain the idea of how atoms are joined together.
a) True
b) False

View Answer

Answer: a [Reason:] Chemical shift allows a chemist to obtain the idea of how atoms are joined together. It is also possible to know the number of particular atoms present in a molecule.

14. Elementary particles such as electrons and nucleus have the property of spin.
a) True
b) False

View Answer

Answer: a [Reason:] Elementary particles such as electrons and nucleus have the property of spin. They are known to behave as if they rotate about an axis.

Set 3

1. A basic X-ray source includes which of the following components?
a) Large target anode
b) Large target cathode
c) Small target anode
d) Small target cathode

View Answer

Answer: a [Reason:] A basic X-ray source includes a large target anode. It also has a heating element.

2. The anode is held at __________ positive potential and the filament is held at ____________ potential.
a) High, ground
b) Ground, high
c) Low, high
d) High, low

View Answer

Answer: a [Reason:] The anode is held at high potential and the filament is held at ground potential. Electrons are accelerated from the filament.

3. Which of the following is one of the most commonly used anode material?
a) Carbon
b) Tungsten
c) Magnesium
d) Cesium

View Answer

Answer: c [Reason:] Magnesium is one of the most commonly used anode material. Aluminium is also commonly used.

4. Which is the most intense line in the X-ray spectrum?
a) Kα1
b) Kα2
c) Kα12
d) Kα22

View Answer

Answer: c [Reason:] Kα12 is the most intense line in the X-ray spectrum. Different lines have specific energies.

5. Which of the following must be used with the X-ray source to have high energy resolution?
a) Chopper
b) Vacuum chamber
c) Accelerator
d) Monochromator

View Answer

Answer: d [Reason:] Monochromator must be used with the X-ray source to have high energy resolution. It will also remove the satellite lines.

6. Magnetic deflection energy analysers are effective than electrostatic types.
a) True
b) False

View Answer

Answer: a [Reason:] Magnetic deflection energy analysers are effective than electrostatic types. It is less convenient to design and use.

7. Double-pass cylindrical mirror energy analyser has how many mirrors?
a) One
b) Two
b) Three
d) Four

View Answer

Answer: b [Reason:] Double-pass cylindrical mirror energy analyser has two mirrors. It is commonly used in electron spectroscopy.

8. In spherical sector analyser, __________ is detected and plotted as a function of energy.
a) Mass
b) Charge
c) Number of electrons striking the detector
d) Mass to charge ratio

View Answer

Answer: c [Reason:] In spherical sector analyser, number of electrons striking the detector is detected and plotted as a function of energy. It is detected for a constant potential.

9. Which of the following is the most commonly used detector in ESCA and AES?
a) Electron multiplier
b) Dynodes
c) Photovoltaic cell
d) Photomultiplier

View Answer

Answer: a [Reason:] Electron multiplier is the most commonly used detectors in ESCA and AES. It is similar to photomultiplier.

10. Electron detector has a _______ doped glass tube with a secondary semiconducting coating.
a) Quartz
b) Silica
c) Lead
d) Cesium

View Answer

Answer: c [Reason:] Electron detector has a lead doped glass tube with a secondary semiconducting coating. It has a high secondary electron shield.

11. The output of the multiplier is fed to which of the following immediately?
a) Pulse amplifier discriminator
b) DAC
c) ADC
d) Multichannel analyser

View Answer

Answer: a [Reason:] The output of the multiplier is fed to pulse amplifier discriminator. It is then fed to a multichannel analyser.

12. Which of the following is the ideal vacuum for electron spectrometers?
a) 10-6 torr
b) 10-7 torr
c) 10-8 torr
d) 10-9 torr

View Answer

Answer: a [Reason:] 10-6 torr is the ideal vacuum for electron spectrometers. Vacuum below 10-6 torr can also be used.

13. Which of the following is the most commonly used magnetic shielding?
a) Helmholtz coils
b) Ferro-magnetic shielding
c) Faraday shield
d) Magnetometer probe

View Answer

Answer: b [Reason:] Ferro-magnetic shielding is the most commonly used magnetic shielding. Helmholtz coil can be used as alternative.

14. Charging effect can be suppressed by supplying flood of electrons having which of the following?
a) Uniform low energy
b) Uniform low mass
c) Uniform high energy
d) Uniform high mass

View Answer

Answer: a [Reason:] Charging effect can be suppressed by supplying flood of electrons having uniform low energy. It also results in attainment of additional useful information.

15. Synchroton radiation has several advantages over conventional radiation.
a) True
b) False

View Answer

Answer: a [Reason:] Synchroton radiation has several advantages over conventional radiation. The resolution is very high.

Set 4

1. ICP’s principle is similar to which of the following?
a) Flame emission spectroscopy
b) Fourier transforms spectroscopy
c) Atomic emission spectroscopy
d) Absorption spectroscopy

View Answer

Answer: c [Reason:] ICP’s principle is similar to atomic emission spectroscopy. Samples are decomposed to neural elements in argon plasma in this method.

2. ICP is used to analyse samples in which of the following states?
a) Solids
b) Liquids
c) Gases
d) Solids and liquids

View Answer

Answer: d [Reason:] ICP is used to analyse samples in both solid and liquid states. Atomic emission spectrometer is used to analyse only solid samples.

3. Solid samples are introduced into the ICP spectrometer using which of the following?
a) Nebulizer
b) Curvette having glass windows
c) Probe
d) Laser ablation system

View Answer

Answer: d [Reason:] ICP spectrometer can be used for solid samples. They are introduced using laser ablation system.

4. Liquid samples are introduced into the ICP spectrometer using which of the following?
a) Nebulizer
b) Curvette having glass windows
c) Probe
d) Laser ablation system

View Answer

Answer: a [Reason:] ICP spectrometer can be used for liquid samples. Aqueous samples are introduced using nebulizer.

5. Atomisation or ionisation occurs at which of the following conditions?
a) Vacuum pressure
b) Atmospheric pressure
c) Low pressure
d) High pressure

View Answer

Answer: d [Reason:] Atomization or ionisation occurs at atmospheric pressure. The interface between the ICP and MS components are crucial in creating a vacuum.

6. Ions flow is pumped into the vacuum system using which of the following?
a) Orifice
b) Nozzle
c) Venturi meter
d) Dall tube

View Answer

Answer: a [Reason:] Ions flow is pumped into the vacuum system using orifice. It expands in the vacuum system.

7. Which of the following is not the characteristic of ICP spectrometer?
a) Easy sample introduction
b) It can trace multiple elements
c) High detection limits
d) Accurate

View Answer

Answer: c [Reason:] ICP spectrometer has low detection limits of mass spectrometer. It is capable of tracing multiple elements.

8. ICP spectrometer is a sequential multi-element analyser that has scan times less than ____
for one sweep.
a) 10ms
b) 20ms
c) 50ms
d) 100ms

View Answer

Answer: b [Reason:] ICP spectrometer is a sequential multi-element analyser that has scan times less than 20ms for one sweep. Quadrupole mass analyser gives better unit mass resolution.

9. Double focussing section analysers offer better resolution than ICP spectrometry system.
a) True
b) False

View Answer

Answer: a [Reason:] Double focussing section analysers offer better resolution than ICP spectrometry system. Their disadvantage is that they are large and have high capital cost.

10. The most common type of ion detector found in ICP system is which of the following?
a) Faraday cup collector
b) Channeltron
c) Micro-channel plate
d) Flame ionization detector

View Answer

Answer: b [Reason:] The most common type of ion detector found in ICP system is channeltron electron multiplier. It is a cone or horn shaped tube.

11. Which of the following is the most accurate method of determination of elemental
composition?
a) Spectroscopy
b) Isotope dilution
c) Isobar dilution
d) Chromatography

View Answer

Answer: b [Reason:] The most accurate method of determination of elemental composition is isotope dilution. It permits calculation of concentration of an element.

12. Which of the following is the disadvantage of ICP mass spectroscopy?
a) Incapable of multi-element analysis
b) Less sensitivity
c) Impossible to obtain isotopic information
d) Not useful for detection of non-metals

View Answer

Answer: d [Reason:] ICP mass spectroscopy has multi-element capability and high sensitivity. It is not capable of multi-element analysis.

13. The isobaric interference is not caused in which of the following elements?
a) Argon
b) Oxygen
c) Helium
d) Nitrogen

View Answer

Answer: c [Reason:] The isobaric interference is not caused due to isotopes of helium. It is caused by isotopes of argon, oxygen and nitrogen.

Set 5

1. 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

View Answer

Answer: b [Reason:] In total reflection X-ray fluorescence spectrometer, the specimen is excited by the primary X-ray beam at a grazing angle less than the critical angle. Total internal reflection occurs at the critical angle.

2. 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

View Answer

Answer: b [Reason:] The x-ray beam produced by the primary x-ray tube passes through the slit-collimator arrangement. This forms the incident radiation.

3. Which of the following crystals are polished to act as the cut-off reflector?
a) Quartz
b) Beryllium
c) Silicon
d) Lithium

View Answer

Answer: c [Reason:] Quartz crystals are polished to act as the cut-off reflector. It is mounted on the first reflector stage.

4. The suppression of high energy bremsstrahlung radiation improves which of the following?
a) Signal to background ratio
b) Accuracy
c) Sensitivity
d) Coherence

View Answer

Answer: a [Reason:] The suppression of high energy bremsstrahlung radiation improves signal to background ratio. Hence, it is performed in total reflection X-ray fluorescence spectrometer.

5. Which of the following components are used as the sample carrier?
a) Curvette
b) Flask
c) Capillary tube
d) Float glass

View Answer

Answer: d [Reason:] Float glass is used as the sample carrier. It is mounted as the second reflector stage.

6. Which of the following devices are used as detector?
a) Thermistor
b) Optical detector
c) Solid state detector
d) Golay cell

View Answer

Answer: c [Reason:] The detection system comprises of peltier cooled solid state detector. It also has a spectroscopy amplifier.

7. Which of the following happens when 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

View Answer

Answer: a [Reason:] When detector is placed very close to the sample, the maximum efficiency increases. This is because large angle is intercepted.

8. To monitor the primary beam, which of the following is used?
a) Scintillation counter
b) GM counter
c) Gamma counter
d) Proportional counter

View Answer

Answer: b [Reason:] To monitor the primary beam, Gm counter is used. It is placed in the specular reflection direction.

9. The major problem associated with sample preparation is which of the following?
a) Preparing sample in right quantity
b) Choosing sample holders
c) Matrix effects
d) Reflection by holders

View Answer

Answer: c [Reason:] The major problem associated with sample preparation is matrix effects. The primary and emitted radiation is absorbed by the element present along with the elements of interest.

10. Computer-controlled corrective iteration is the only reliable method of matrix effects correction.
a) True
b) False

View Answer

Answer: a [Reason:] Computer-controlled corrective iteration is the only reliable method of matrix effects correction. This is used in places where an unknown matrix occurs.

11. In computer-controlled corrective iteration method, which of the following is used to estimate absorption corrections?
a) Initial raw intensity data
b) Elemental composition
c) Amount of sample
d) Amount of radiation

View Answer

Answer: a [Reason:] In computer-controlled corrective iteration method, initial raw intensity data is used to estimate absorption corrections. Elemental composition is used to calculate absorption corrections.

12. Total reflection X-ray fluorescence spectrometer is attractive for elements which lack reliable wet chemical methods.
a) True
b) False

View Answer

Answer: a [Reason:] Total reflection X-ray fluorescence spectrometer is attractive for elements which lack reliable wet chemical methods. Example for such elements are tantalum and rare earth metals.