92 + Interview Questions in Colorimetry And Spectrometry in Analytical Instrumentation Page 1 InterviewSolution

1.	Spectroscopy deals with interaction of electromagnetic radiation with matter. What is the speed of this radiation in vacuum in m/s?(a) 6 x 10^8(b) 5 x 10^8(c) 7 x 10^8(d) 3 x 10^8I had been asked this question by my school teacher while I was bunking the class.This question is from Spectral Method of Analysis in chapter Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Correct ANSWER is (d) 3 x 10^8 Explanation: SPEED of light is ALSO the speed of all ELECTROMAGNETIC radiations. Speed of light is 3 x 10^8m/s.

Discussion

2.	Which type of Quantum Transition takes place in Ultra Violet and Visible spectroscopy?(a) Rotation of molecules(b) Nuclear(c) Bonding electrons(d) Spin of nuclei in a magnetic fieldThis question was posed to me in examination.I'd like to ask this question from Spectral Method of Analysis topic in section Colorimetry and Spectrometry of Analytical Instrumentation
Answer» CORRECT choice is (C) Bonding electrons The explanation: In UV and Visible Spectroscopy, type of Quantum Transmission is Bonding electrons. The REST of the options are Quantum Transmission type of other spectroscopic METHODS.

Discussion

3.	Which of the following is not a property or parameter of electromagnetic radiation?(a) Wavelength(b) Voltage(c) Wave number(d) AmplitudeI have been asked this question in my homework.My doubt is from Spectral Method of Analysis in section Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The correct CHOICE is (b) Voltage Explanation: WAVELENGTH, AMPLITUDE and WAVENUMBER are parameters of electromagnetic radiation. Other parameters are Velocity and Frequency.

Discussion

4.	Which of the following is not a type of Spectroscopy?(a) Gamma ray(b) X ray(c) Nuclear magnetic resonance(d) SoundThis question was posed to me in a national level competition.My query is from Spectral Method of Analysis topic in portion Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Correct option is (d) SOUND The EXPLANATION: Sound is not a type of electromagnetic radiation. HENCE, it is not a type of SPECTROSCOPY.

Discussion

5.	Electromagnetic radiation can travel through a vacuum.(a) True(b) FalseThis question was posed to me in an interview for job.My question is taken from Spectral Method of Analysis topic in portion Colorimetry and Spectrometry of Analytical Instrumentation
Answer» CORRECT option is (a) True For explanation I would say: Electromagnetic RADIATION can travel through a vacuum. It does not NEED a MEDIUM for propagation.

Discussion

6.	Which of the following is false about the wavelengths of electromagnetic radiation?(a) Radiation with short wavelengths have high energies(b) Energy does not depend on wavelength(c) Radiation with long wavelengths have low energies(d) Energy depends on wavelengthThe question was posed to me in an interview for job.This interesting question is from Spectral Method of Analysis in portion Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Right choice is (B) Energy does not depend on wavelength For EXPLANATION: The radiations with short wavelength have high ENERGIES and vice versa. THUS, energy depends on wavelength.

Discussion

7.	How is the wave number of electromagnetic radiation related to wavelength?(a) It is the reciprocal of wavelength(b) It is directly proportional to wavelength(c) It is not related to wavelength(d) It is equal to wavelengthThis question was posed to me in an interview.This interesting question is from Spectral Method of Analysis topic in chapter Colorimetry and Spectrometry of Analytical Instrumentation
Answer» RIGHT ANSWER is (a) It is the reciprocal of wavelength Explanation: Wave NUMBER is the number of waves spread in a length of one centimeter. It is the reciprocal of wavelength.

Discussion

8.	Which of the following is the wavelength of microwave radiation?(a) 10 – 780nm(b) 0.78 – 30µm(c) 0.6 – 10 m(d) 0.75 – 3.75 mmI got this question in an interview for internship.My query is from Spectral Method of Analysis in portion Colorimetry and Spectrometry of Analytical Instrumentation
Answer» RIGHT CHOICE is (d) 0.75 – 3.75 MM The EXPLANATION is: The wavelength of Microwave RADIATION is 0.75 – 3.75 mm. The rest of the options are the wavelength of other Electro Magnetic radiations.

Discussion

9.	Velocity of electromagnetic radiation is more in a vacuum than in any medium.(a) True(b) FalseThe question was posed to me at a job interview.My doubt stems from Spectral Method of Analysis in section Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Correct choice is (a) True Easy explanation: VELOCITY of electromagnetic RADIATION tends to decrease when a MEDIUM is PRESENT. Hence, it attains maximum speed in a vacuum.

Discussion

10.	Which of the following is the wavenumber of UV and Visible radiation?(a) 1 x 10^6 to 1.3 x 10^4 m^-1(b) 1 x 10^6 to 1.3 x 10^4 m(c) 13 – 27 m^-1(d) 1 x 10^6 to 1.3 x 10^4 m^2The question was asked during an interview for a job.This interesting question is from Spectral Method of Analysis in division Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Right CHOICE is (a) 1 x 10^6 to 1.3 x 10^4 m^-1 The EXPLANATION: Wave number of UV, Visible radiation is 1 x 10^6 to 1.3 x 10^4 m^-1. Wave number is the reciprocal of wavelength. So, the unit is m^-1.

Discussion

11.	Beer Lambert’s law gives the relation between which of the following?(a) Reflected radiation and concentration(b) Scattered radiation and concentration(c) Energy absorption and concentration(d) Energy absorption and reflected radiationThis question was addressed to me in unit test.Asked question is from Introduction to UV Visible Spectrometers topic in division Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Correct answer is (c) Energy absorption and concentration The BEST I can EXPLAIN: Beer Lambert’s LAW GIVES the relation between Energy absorption and Concentration. It was proposed by Beer and Lambert.

Discussion

12.	In which of the following ways, absorption is related to transmittance?(a) Absorption is the logarithm of transmittance(b) Absorption is the reciprocal of transmittance(c) Absorption is the negative logarithm of transmittance(d) Absorption is a multiple of transmittanceI got this question in a job interview.The origin of the question is Introduction to UV Visible Spectrometers in chapter Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Correct OPTION is (c) Absorption is the negative logarithm of TRANSMITTANCE To explain I would say: Transmittance is the RATIO of the radiant power transmitted by a SAMPLE to the radiant power incident on the sample. Absorption is the negative logarithm of transmittance.

Discussion

13.	Which of the following is not a limitation of Beer Lambert’s law, which gives the relation between absorption, thickness and concentration?(a) Concentration must be lower(b) Radiation must have higher bandwidth(c) Radiation source must be monochromatic(d) Does not consider factors other than thickness and concentration that affect absorbanceThis question was addressed to me by my college professor while I was bunking the class.My doubt is from Introduction to UV Visible Spectrometers topic in section Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Right choice is (b) RADIATION must have HIGHER bandwidth The EXPLANATION is: The LAW is derived assuming that the radiation is MONOCHROMATIC. So, if bandwidth increases it will create deviation.

Discussion

14.	Beer’s law states that the intensity of light decreases with respect to ___________(a) Concentration(b) Distance(c) Composition(d) VolumeI have been asked this question at a job interview.Query is from Introduction to UV Visible Spectrometers in division Colorimetry and Spectrometry of Analytical Instrumentation
Answer» RIGHT answer is (a) Concentration The BEST I can explain: BEER’s law states that the intensity of light decreases with the concentration of the MEDIUM. It was stated by Beer.

Discussion

15.	Which of the following is not true about Absorption spectroscopy?(a) It involves transmission(b) Scattering is kept minimum(c) Reflection is kept maximum(d) Intensity of radiation leaving the substance is an indication of a concentrationI have been asked this question in my homework.This intriguing question originated from Introduction to UV Visible Spectrometers in chapter Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Right ANSWER is (c) Reflection is kept maximum To explain I would SAY: In Absorption spectroscopy, reflection must also be kept minimum ALONG with SCATTERING. Amount of absorption DEPENDS on the number of molecules in the material.

Discussion

16.	Lambert’s law states that the intensity of light decreases with respect to __________(a) Concentration(b) Distance(c) Composition(d) VolumeI have been asked this question in an online interview.My question comes from Introduction to UV Visible Spectrometers in chapter Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The correct choice is (B) Distance For explanation: LAMBERT’s law states that the intensity of light decreases with RESPECT to the CONCENTRATION of the medium. It was stated by Lambert.

Discussion

17.	The representation of Beer Lambert’s law is given as A = abc. If ‘b’ represents distance, ‘c’ represents concentration and ‘A’ represents absorption, what does ‘a’ represent?(a) Intensity(b) Transmittance(c) Absorptivity(d) AdmittanceThe question was posed to me during an interview.I need to ask this question from Introduction to UV Visible Spectrometers in division Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Right answer is (C) ABSORPTIVITY To explain I would say: ‘a’ represents the absorption constant. It is also known as absorptivity.

Discussion

18.	What is the unit of absorbance which can be derived from Beer Lambert’s law?(a) L mol^-1 cm^-1(b) L gm^-1 cm^-1(c) Cm(d) No unitThe question was asked in an interview for job.Asked question is from Introduction to UV Visible Spectrometers in section Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Right answer is (d) No unit The best I can explain: ABSORBANCE has no unit. The units of ABSORPTIVITY, DISTANCE and concentration CANCEL each other. Hence, ABSORPTION has no unit.

Discussion

19.	Transmittance is given as T = P/Po. If Po is the power incident on the sample, what does P represent?(a) Radiant power transmitted by the sample(b) Radiant power absorbed by the sample(c) Sum of powers absorbed and scattered(d) Sum of powers transmitted and reflectedThe question was asked in a job interview.The doubt is from Introduction to UV Visible Spectrometers in division Colorimetry and Spectrometry of Analytical Instrumentation
Answer» CORRECT OPTION is (a) RADIANT power transmitted by the SAMPLE To explain I would say: P represents radiant power transmitted by the sample. Transmittance is the RATIO of radiant power transmitted by the sample to the radiant power that is incident on it.

Discussion

20.	What is the unit of molar absorptivity or absorptivity which is used to determine absorbance A in Beer Lambert’s formula?(a) L mol^-1 cm^-1(b) L gm^-1 cm^-1(c) Cm(d) No unitI have been asked this question in my homework.The doubt is from Introduction to UV Visible Spectrometers in chapter Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The CORRECT option is (a) L mol^-1 cm^-1 To explain: The unit of ABSORPTIVITY is L mol^-1 cm^-1. If concentration is represented as GM per litre it becomes L gm^-1 cm^-1.

Discussion

21.	Which is the missing block in the block diagram for Absorption of Radiation Instrument given below?(a) Filter(b) Reflector(c) Converging lens(d) DetectorThe question was posed to me in exam.This question is from Absorption Instrumentation and Block Diagram Representation topic in section Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Correct option is (d) Detector Explanation: To measure the AMOUNT of RADIATION ABSORBED and transmitted detector is very IMPORTANT. It detects the amount of radiation which is then inferred using read out device.

Discussion

22.	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 reflectorThe question was asked in an interview.My question is from Absorption Instrumentation and Block Diagram Representation topic in division Colorimetry and Spectrometry of Analytical Instrumentation
Answer» RIGHT option is (b) PHOTOVOLTAIC cell The BEST explanation: Photovoltaic cell does not require a battery for operation. Its working is entirely different from Photomultiplier tube or Photoemissive tubes.

Discussion

23.	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 reflectorI had been asked this question in an interview for internship.Origin of the question is Absorption Instrumentation and Block Diagram Representation topic in division Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The correct answer is (a) Photomultiplier tube The best I can explain: PMT is used for DETECTION of light intensities which are WEAK. As the NAME suggests, Photomultiplier tube multiplies the incident electrons using DYNODES causing an AVALANCHE of electrons.

Discussion

24.	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 gasI have been asked this question in class test.My question is based upon Absorption Instrumentation and Block Diagram Representation topic in division Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The correct ANSWER is (b) Iodine is added to NORMAL FILLING gas Easy explanation: In Tungsten filament lamp tungsten filament is ENCLOSED in a bulb of GLASS filled with inert gas or vacuum. In Tungsten Halogen lamp iodine is added to the normal filling glass.

Discussion

25.	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 environmentI got this question in an interview.My question is from Absorption Instrumentation and Block Diagram Representation in portion Colorimetry and Spectrometry of Analytical Instrumentation
Answer» CORRECT choice is (c) They deteriorate due to absorption of heat leading to changes in GELATIN For EXPLANATION: With the absorption of heat they deteriorate due to changes in gelatin. Bleaching of DYE OCCURS.

Discussion

26.	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 voltageThis question was posed to me at a job interview.Origin of the question is Absorption Instrumentation and Block Diagram Representation in division Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Right answer is (d) By controlling the SOURCE VOLTAGE The explanation is: The intensity of radiation in the incandescent source is proportional to the LAMP source voltage. THEREFORE, by controlling the source voltage stability can be ACHIEVED.

Discussion

27.	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(d) Space layer is made of a substance having low refractive indexThis question was posed to me in exam.This interesting question is from Absorption Instrumentation and Block Diagram Representation in section Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The correct choice is (a) It permits continuous selection of different WAVELENGTH For explanation: It ALLOWS continuous selection of wavelength by using a spacer FILM of graded thickness. Rest of the options are properties of normal interference filters.

Discussion

28.	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) AgNO3This question was posed to me during an interview.My doubt is from Absorption Instrumentation and Block Diagram Representation in chapter Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The correct ANSWER is (b) MgF2 Easy EXPLANATION: MgF2 is used as layer of DIELECTRIC in INTERFERENCE filters. Other material that can be used is ZnS.

Discussion

29.	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 copperThe question was asked in an international level competition.My query is from Absorption Instrumentation and Block Diagram Representation topic in portion Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Correct OPTION is (c) Envelope is FABRICATED with QUARTZ To explain: The envelope is fabricated with quartz to allow HIGH operating temperatures. Tungsten filament and inert gas are generally used and are not MODIFIED.

Discussion

30.	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 detectorThe question was asked in an international level competition.I'm obligated to ask this question of Single Beam and Double Beam Instruments in chapter Colorimetry and Spectrometry of Analytical Instrumentation
Answer» RIGHT answer is (b) Beam splitter is used to GET PARALLEL beam Easy EXPLANATION: Single beam instruments make use of one beam. Therefore, beam splitters are not REQUIRED in single beam instruments.

Discussion

31.	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 comparedThe question was asked in exam.This question is from Single Beam and Double Beam Instruments topic in portion Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Correct OPTION is (c) REFERENCE beam must have a higher INTENSITY than SAMPLE beam To elaborate: Reference beam cannot have a higher intensity than sample beam. The beam is split into two beams of equal intensity.

Discussion

32.	Which of the following is not an application of colorimeter?(a) Paints(b) Inks(c) Cosmetics(d) Composition detectionThe question was asked in a national level competition.This question is from Single Beam and Double Beam Instruments in portion Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The correct ANSWER is (d) COMPOSITION detection To elaborate: Colorimeter is not used to determine composition. Its APPLICATION is paints, DYES, inks, COSMETICS and plastics.

Discussion

33.	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) VolumeI have been asked this question by my school teacher while I was bunking the class.My query is from Single Beam and Double Beam Instruments topic in section Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Right option is (a) Transmittance To explain: In photometers, the READING is INITIALLY obtained in the FORM of transmittance as some radiation is ABSORBED by the sample and the REST of the beam is transmitted. This transmitted beam is measured by the detector.

Discussion

34.	Colorimeters are used in applications where great accuracy is required.(a) True(b) FalseThe question was posed to me in class test.My question comes from Single Beam and Double Beam Instruments topic in chapter Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Correct choice is (B) False Explanation: COLORIMETERS are used in applications where GREAT ACCURACY is not required. They are also known as photometers.

Discussion

35.	In the diagram of single beam photometer given below, identify the component that is not marked.(a) Monochromator(b) Absorption filter(c) Sample holder(d) Interference filterThis question was posed to me during an interview.This interesting question is from Single Beam and Double Beam Instruments topic in section Colorimetry and Spectrometry of Analytical Instrumentation
Answer» CORRECT OPTION is (C) Sample holder The BEST I can explain: In single beam SPECTROPHOTOMETER, the beam passed through the sample which is held in the sample holder. The transmitted beam is measured by the detector.

Discussion

36.	Colorimeters are used to determine the concentration of solutions.(a) True(b) FalseThis question was posed to me by my school teacher while I was bunking the class.Question is from Single Beam and Double Beam Instruments topic in section Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Correct ANSWER is (a) True Best explanation: COLORIMETRY is the science of colour measurement. It is used to DETERMINE the CONCENTRATIONS of SOLUTIONS.

Discussion

37.	Which of the following is a source used in spectroscopy?(a) LASER(b) Tube light(c) Sodium vapour lamp(d) Tungsten lampI had been asked this question at a job interview.The origin of the question is Single Beam and Double Beam Instruments in chapter Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The CORRECT choice is (d) Tungsten lamp Explanation: Tungsten lamp is the SOURCE USED in SPECTROSCOPY. It is the source used in UV, Visible spectroscopy.

Discussion

38.	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 photometersI got this question in an interview for job.The query is from Single Beam and Double Beam Instruments topic in division Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The CORRECT ANSWER is (d) Indicates the DIFFERENCE between the OUTPUT of two photometers To ELABORATE: It compares the output of the two photometers obtained using two beams. It indicates the output.

Discussion

39.	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 beamThis question was posed to me during an online exam.Origin of the question is Single Beam and Double Beam Instruments topic in chapter Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The CORRECT answer is (a) SPLITS beam into two equal intensity beams For explanation: Beam splitter splits beam into two equal intensity beams. ONE beam PASSES through the sample and other through the reference.

Discussion

40.	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 wireThe question was asked in an interview.My query is from Instrumentation of IR in division Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The correct answer is (b) HIGH pressure mercury arc lamp To explain: High pressure mercury arc lamp is USED as the source for Far IR SPECTROPHOTOMETER. REST of the options are used as a source in Mid Infrared Spectrophotometer.

Discussion

41.	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^-1I have been asked this question in class test.The query is from Instrumentation of IR in division Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The CORRECT answer is (C) 12500 – 4000 cm^-1 To elaborate: The wave number of near INFRARED SPECTROMETER ranges between 12500 – 4000. Wavenumber is the RECIPROCAL of wavelength.

Discussion

42.	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 ThoriumThe question was asked in an international level competition.My enquiry is from Instrumentation of IR in division Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Right answer is (b) Oxides of Barium Best explanation: Oxides of Barium is not present in Nernst GLOWER. They are constructed by fusing oxides of ZIRCONIUM, YITRIUM and thorium.

Discussion

43.	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 mmThe question was asked in final exam.My query is from Instrumentation of IR topic in section Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Right option is (a) NEAR IR: 0.8 – 2.5 mm To explain I would SAY: Wavelength of near IR is 0.8 – 2.5 mm and for mid IR it is 2.5 – 50 mm. The wavelength of FAR IR is 50 – 1000 mm.

Discussion

44.	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 carbideI have been asked this question in examination.My question is from Instrumentation of IR topic in division Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The correct answer is (a) SILICON CARBIDE Explanation: GLOBAR is a silicon carbide ROD. It is 5mm in diameter and 50mm LONG.

Discussion

45.	Bolometer, a type of detector, is also known as ___________(a) Resistance temperature detector (RTD)(b) Thermistor(c) Thermocouple(d) Golay cellI got this question in class test.My query is from Instrumentation of IR in chapter Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The correct answer is (b) Thermistor Best EXPLANATION: BOLOMETERS are also known as thermistors. It is a TYPE of resistance thermometer constructed of metals such as PLATINUM or nickel.

Discussion

46.	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 filmsThis question was posed to me by my college professor while I was bunking the class.The origin of the question is Instrumentation of IR topic in chapter Colorimetry and Spectrometry of Analytical Instrumentation
Answer» CORRECT ANSWER is (d) Thin films The explanation: Four techniques are GENERALLY used to prepare solid samples. They are: Solids run in SOLUTION, Mull technique, Solid films and PRESSED pellet techniques.

Discussion

47.	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 sulphateThis question was addressed to me in a job interview.The above asked question is from Instrumentation of IR topic in chapter Colorimetry and Spectrometry of Analytical Instrumentation
Answer» CORRECT choice is (d) Tetraglycine SULPHATE To explain I would say: Pyroelectric materials are deutrated triglycine sulphate, triglycine sulphate and some POLYMERS. They give RISE to potential when SUBJECTED to a heating or cooling effect.

Discussion

48.	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 temperatureI had been asked this question during an online interview.This interesting question is from Instrumentation of IR topic in section Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The CORRECT answer is (a) Expansion of gas upon heating To explain: It is also known as pneumatic detector. The gases EXPAND on heating and this in TURN leads to the MOVEMENT of a diaphragm just like in pneumatic sensors.

Discussion

49.	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 chlorideI have been asked this question in a job interview.Query is from Fourier Transform Infra-red Spectrometers topic in division Colorimetry and Spectrometry of Analytical Instrumentation
Answer» The correct choice is (a) Mylar The best I can explain: Generally, mylar is the thin film used in beam SPLITTERS. Beam splitter has to pass 50% of the RADIATION and REFLECT 50% of the radiation.

Discussion

50.	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 solutionI got this question during an internship interview.This is a very interesting question from Instrumentation of IR in portion Colorimetry and Spectrometry of Analytical Instrumentation
Answer» Correct OPTION is (b) Mull TECHNIQUE To ELABORATE: The mentioned technique is Mull technique. This method is used for qualitative analysis but not QUANTITATIVE analysis.

Discussion

Explore topic-wise InterviewSolutions in .

Which of the following is not a property or parameter of electromagnetic radiation?(a) Wavelength(b) Voltage(c) Wave number(d) AmplitudeI have been asked this question in my homework.My doubt is from Spectral Method of Analysis in section Colorimetry and Spectrometry of Analytical Instrumentation

Which of the following is not a type of Spectroscopy?(a) Gamma ray(b) X ray(c) Nuclear magnetic resonance(d) SoundThis question was posed to me in a national level competition.My query is from Spectral Method of Analysis topic in portion Colorimetry and Spectrometry of Analytical Instrumentation

Electromagnetic radiation can travel through a vacuum.(a) True(b) FalseThis question was posed to me in an interview for job.My question is taken from Spectral Method of Analysis topic in portion Colorimetry and Spectrometry of Analytical Instrumentation

Which of the following is the wavelength of microwave radiation?(a) 10 – 780nm(b) 0.78 – 30µm(c) 0.6 – 10 m(d) 0.75 – 3.75 mmI got this question in an interview for internship.My query is from Spectral Method of Analysis in portion Colorimetry and Spectrometry of Analytical Instrumentation

Velocity of electromagnetic radiation is more in a vacuum than in any medium.(a) True(b) FalseThe question was posed to me at a job interview.My doubt stems from Spectral Method of Analysis in section Colorimetry and Spectrometry of Analytical Instrumentation

Colorimeters are used in applications where great accuracy is required.(a) True(b) FalseThe question was posed to me in class test.My question comes from Single Beam and Double Beam Instruments topic in chapter Colorimetry and Spectrometry of Analytical Instrumentation

Colorimeters are used to determine the concentration of solutions.(a) True(b) FalseThis question was posed to me by my school teacher while I was bunking the class.Question is from Single Beam and Double Beam Instruments topic in section Colorimetry and Spectrometry of Analytical Instrumentation

Bolometer, a type of detector, is also known as ___________(a) Resistance temperature detector (RTD)(b) Thermistor(c) Thermocouple(d) Golay cellI got this question in class test.My query is from Instrumentation of IR in chapter Colorimetry and Spectrometry of Analytical Instrumentation