117 + Interview Questions in Ph Meters And Ion Analysers in Analytical Instrumentation Page 2 InterviewSolution

51.	The biocatalytic membrane is attached to the glass electrode using which of the following materials?(a) Nylon mesh(b) Teflon(c) Silicon rubber(d) PolytheneThis question was posed to me in homework.Question is from Special Designs of Ion Selective Electrodes topic in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Right ANSWER is (a) NYLON MESH Explanation: The biocatalytic MEMBRANE is attached to the glass ELECTRODE using nylon mesh. Cellophane film can also be used.

Discussion

52.	If a solid or liquid membrane is placed in pure water, the membrane dissolves slightly, producing an equilibrium concentration of the measured ion. This is represented as __________(a) A constant, Eo(b) Activity(c) Blank correction, Cb(d) Concentration of standard solution, CsThe question was posed to me in an interview.Origin of the question is Ion Analyser in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» CORRECT option is (C) Blank correction, CB Explanation: If a SOLID or liquid membrane is placed in pure water, the membrane dissolves slightly, producing an equilibrium concentration of the measured ion. This is represented as a blank correction, Cb. This is the constant BACKGROUND for all measurements.

Discussion

53.	Calomel electrode can behave as which of the following components?(a) Anode only(b) Cathode only(c) Anode or cathode(d) Salt bridgeThis question was posed to me in class test.My enquiry is from Secondary Reference Electrodes topic in chapter pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Correct option is (C) ANODE or cathode Easiest explanation: CALOMEL electrode can behave as anode or cathode depending UPON the half cell. A SALT bridge is used for coupling.

Discussion

54.	The measurement of hydrogen ion concentration can be made by measuring the potential developed in an electrochemical cell.(a) True(b) FalseThe question was posed to me during an online interview.My enquiry is from pH Measurement and Types topic in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Correct option is (a) True The EXPLANATION is: The measurement of hydrogen ION concentration can be made by MEASURING the POTENTIAL DEVELOPED in an electrochemical cell.

Discussion

55.	When the calomel electrode acts as the cathode which of the following does not occur?(a) Mercury ions are discharged at the electrode(b) More calomel passes into the solution(c) There is a decrease in the concentration of chloride ions(d) There is an increase in the concentration of chloride ionsI have been asked this question by my school teacher while I was bunking the class.My question is taken from Secondary Reference Electrodes topic in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The CORRECT ANSWER is (d) There is an increase in the concentration of chloride ions Explanation: When the calomel electrode acts as the CATHODE. When the calomel electrode acts as the cathode, mercury ions are discharged at the electrode. More calomel passes into the SOLUTION. HENCE, there is an increase in the concentration of chloride ions.

Discussion

56.	In combination electrodes, both the electrodes must be maintained at different temperatures.(a) True(b) FalseThe question was asked in an international level competition.I'm obligated to ask this question of Combination Electrode topic in division pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Correct choice is (b) False The BEST explanation: In COMBINATION electrodes, both the electrodes must be maintained at the same temperature. MEASURING error due to small temperature differences between the BUFFER solution and the sample are negligible.

Discussion

57.	Ion selective electrodes have ________ linear range and _________ detection limit than the pH electrode.(a) Lower, lower(b) Lower, higher(c) Higher, lower(d) Higher, higherThis question was addressed to me in quiz.I would like to ask this question from Ion Selective Electrodes-Principle and Types topic in chapter pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The correct option is (b) LOWER, higher The explanation is: Ion SELECTIVE electrodes have a lower linear range and higher detection limit than the PH ELECTRODE. It works on effectively narrow pH.

Discussion

58.	The zero stability of vibrating condenser amplifier type pH meter is much better than a direct coupled amplifier.(a) True(b) FalseThe question was posed to me in a job interview.I would like to ask this question from pH Meters topic in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» RIGHT choice is (a) True For explanation I WOULD say: The zero stability of vibrating CONDENSER amplifier type pH meter is much better than a direct coupled amplifier. The capacity can be changed by vibrating ONE of its plates.

Discussion

59.	In glucose electrode, glucose oxidase has been coupled to an electrode by which of the following materials?(a) Ferrocene derivatives(b) Urease(c) Polyacrylamide(d) BiochipsI have been asked this question in an interview for job.The query is from Biosensors in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The CORRECT choice is (a) Ferrocene DERIVATIVES The best I can explain: In glucose electrode, glucose oxidase has been coupled to an electrode by using ferrocene derivatives. It is used to measure BLOOD glucose in diabetic patients.

Discussion

60.	If an instrument fails to balance at zero, it is most likely that the electrodes are defective.(a) True(b) FalseI had been asked this question in an interview for internship.The origin of the question is pH Meters in chapter pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Correct choice is (B) False Easy explanation: If an INSTRUMENT FAILS to balance at zero, it is most LIKELY that the electronic circuitry is defective. Errors may also OCCUR due to leakage of capacitance.

Discussion

61.	Given below is the block diagram of digital pH meter. Identify the unmarked component.(a) Filter(b) Buffer(c) A/D converter(d) D/A converterThis question was posed to me in an interview for job.Question is from pH Meters topic in portion pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Right CHOICE is (c) A/D converter For explanation I would say: The unmarked component is A/D converter. Microprocessor operates only on digital DATA. Electrodes give ANALOG SIGNALS. Hence, A/D converter MUST be present.

Discussion

62.	Biocatalytic membrane electrode cannot be used for the measurement of which of the following gases?(a) Ammonia(b) Carbon dioxide(c) Hydrogen(d) NitrogenThe question was asked during an interview for a job.This is a very interesting question from Special Designs of Ion Selective Electrodes topic in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» CORRECT OPTION is (d) NITROGEN The explanation: Biocatalytic membranes cannot be USED for the measurement of nitrogen. It can be used for the measurement of other three gases.

Discussion

63.	The biocatalytic membrane used in the ammonia selective electrode is which of the following?(a) Urea(b) Urease(c) Acrylamide(d) PolyacrylamideThe question was posed to me during an interview.This interesting question is from Special Designs of Ion Selective Electrodes topic in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The correct option is (b) UREASE Explanation: The BIOCATALYTIC membrane USED in the ammonia selective electrode is urease. It is used for the DETECTION of ammonia.

Discussion

64.	The response time of the biocatalytic electrode is a function of the thickness of the enzyme layer.(a) True(b) FalseI had been asked this question in exam.I'm obligated to ask this question of Special Designs of Ion Selective Electrodes topic in chapter pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The correct option is (a) True Explanation: The response TIME of the biocatalytic electrode is a function of the THICKNESS of the enzyme layer. It is also a function of diffusion of the layer in the SAMPLE solution.

Discussion

65.	Hydrogen electrode which is the reference electrode can be used as which of the following?(a) Anode only(b) Cathode only(c) Anode or Cathode(d) Salt bridgeThis question was posed to me in an international level competition.The doubt is from Hydrogen and Glass Electrodes topic in portion pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Right answer is (c) Anode or Cathode To explain I WOULD SAY: HYDROGEN electrode which is the reference electrode can be used as the anode or the cathode. It depends on the half-cell to which it is COUPLED.

Discussion

66.	Which of the following is the relation between the concentration of hydrogen and hydroxyl ions in a basic solution?(a) Value of hydrogen ion concentration is greater(b) Value of hydroxyl ion concentration is greater(c) They are both always the same(d) The concentrations keep changingThe question was asked during an interview for a job.This interesting question is from pH Measurement and Types topic in chapter pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Correct option is (b) Value of HYDROXYL ion CONCENTRATION is greater Explanation: In BASIC solution, the value of hydroxyl ion concentration is greater than that of HYDROGEN ion concentration. It can be represented as [H+]<[OH-].

Discussion

67.	Given below is a diagram of hydrogen electrode. Identify the unmarked component.(a) Hydrogen at 1 atm(b) Hydrogen at 10 atm(c) Helium at 1 atm(d) Helium at 10 atmI got this question during an interview for a job.My doubt is from Hydrogen and Glass Electrodes topic in chapter pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The CORRECT CHOICE is (a) Hydrogen at 1 atm For EXPLANATION: Hydrogen at 1 atm is sent through the side tube. The electrode is placed in a solution of 1M Hcl.

Discussion

68.	Which of the following is not the characteristic of chopper amplifier pH meter?(a) Direct voltage from the electrodes is chopped at the main frequency(b) Using choppers for high-input resistance gives rise to spikes of waveforms at the output(c) It leads to stability in DC output of phase-sensitive rectifier(d) Magnitude of surge increases in the glass electrode outputThe question was asked in homework.Query is from pH Meters topic in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Correct option is (C) It leads to stability in DC output of phase-sensitive rectifier For explanation I would say: The USE of chopper amplifier in PH meter leads to zero instability. It leads to VARIOUS other problems for high-input resistance.

Discussion

69.	Given below is the diagram of liquid membrane electrode. Identify the unmarked component.(a) Solid material(b) Semi-permeable membrane(c) Hydrophobic material(d) Water absorbing materialThe question was posed to me during an online interview.Origin of the question is Ion Selective Electrodes-Principle and Types in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Right option is (c) HYDROPHOBIC material The best EXPLANATION: The unmarked component is porous hydrophobic material. It HOLDS the liquid ion exchanger.

Discussion

70.	During which of the following conditions is the blank correction necessary?(a) If sample concentration rises in linear response region(b) If sample concentration falls in linear response region(c) If sample concentration rises in non-linear response region(d) If sample concentration falls in non-linear response regionThe question was posed to me in an online quiz.This key question is from Ion Analyser in division pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The correct CHOICE is (d) If sample concentration falls in non-linear RESPONSE region Easy explanation: The blank correction is necessary if sample concentration falls in non-linear response region. This is the constant background for all measurements.

Discussion

71.	Given below is the diagram of biosensor. Identify the unmarked component.(a) Microprocessor(b) Filter(c) Transducer(d) A/D converterI got this question during an internship interview.Query is from Biosensors topic in division pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Right option is (C) Transducer Explanation: The biological signals must be converted into ELECTRICAL signals. TRANSDUCERS are USED for this PURPOSE.

Discussion

72.	Which of the following cannot form the inner reference electrode in glass electrodes?(a) Silver electrode(b) Copper electrode(c) Calomel electrode(d) Silver chloride electrodeThis question was addressed to me in a job interview.The origin of the question is Hydrogen and Glass Electrodes topic in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Right answer is (b) Copper electrode To elaborate: Copper electrode cannot form the INNER reference electrode in GLASS ELECTRODES. Inner reference electrode is IMMERSED in a BUFFER solution.

Discussion

73.	In which of the following ways can zero drift be reduced in pH meters?(a) Using filter(b) Giving zero adjustment arrangement(c) Keeping the input impedance high(d) Using balanced and differential amplifiersThis question was posed to me in an interview for job.Enquiry is from pH Meters topic in portion pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Correct option is (d) Using balanced and differential AMPLIFIERS Explanation: Zero drift be reduced in PH meters using balanced and differential amplifiers. Their response to EXTERNAL signals are ADDITIVE and to internal noise are subtractive.

Discussion

74.	In vibrating condenser amplifier type pH meter, to maintain good performance which of the following has to be done?(a) Frequency of the vibrator should be stable(b) Frequency of the vibrator should be constant(c) Amplitude of the vibrator should be constant(d) Both frequency and amplitude of the vibrator should be constant and stableI got this question during an interview.I would like to ask this question from pH Meters in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The CORRECT answer is (d) Both frequency and AMPLITUDE of the vibrator should be constant and stable Easy EXPLANATION: In vibrating condenser amplifier type pH METER, to maintain GOOD performance, both frequency and amplitude of the vibrator should be constant and stable.

Discussion

75.	In glass membrane electrode, the glass containing 11% Na2O, 18% Al2O3, 71% SiO2 is highly sensitive to which of the following ions?(a) Sodium(b) Hydrogen(c) Nitrogen(d) ChlorineThe question was posed to me by my school teacher while I was bunking the class.Asked question is from Ion Selective Electrodes-Principle and Types in portion pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Right answer is (a) Sodium The best I can explain: In glass membrane electrode, the glass containing 11% NA2O, 18% AL2O3, 71% SiO2 is highly sensitive to sodium IONS. Glass ELECTRODES can be used to measure various ions by CHANGING the glass membrane composition.

Discussion

76.	The dilution of solution must not reduce the level of ammonia below _________(a) 10^-2 M(b) 10^-5 M(c) 10^-8 M(d) 10^-9 MThe question was posed to me in semester exam.Enquiry is from Ammonia and Fluoride Electrode topic in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The correct option is (b) 10^-5 M The best I can explain: The DILUTION of solution must not reduce the level of AMMONIA below 10^-5 M. The total level of dissolved species must be below 1M.

Discussion

77.	Which of the following is the effective concentration measured at the electrode head?(a) Selectivity coefficient(b) Ionic strength(c) Activity(d) Activity coefficientThe question was posed to me in an international level competition.The doubt is from Ion Selective Electrodes-Principle and Types in portion pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The CORRECT choice is (c) Activity Explanation: Activity is the effective concentration MEASURED at the ELECTRODE head. Concentration is different from the activity.

Discussion

78.	Which of the following is not the advantage of gel-filled electrodes?(a) Low maintenance(b) Rugged in construction(c) Easy to maintain(d) Does not cause cloggingThe question was asked in quiz.This interesting question is from Combination Electrode in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» CORRECT option is (d) Does not CAUSE clogging Easiest explanation: Gel-filled electrodes cause clogging. HENCE, the output becomes LESS accurate.

Discussion

79.	Pure water is known to be which of the following?(a) Weak electrolyte(b) Strong electrolyte(c) Neither weak nor strong(d) Not an electrolyteI have been asked this question in a national level competition.This key question is from pH Measurement and Types in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Right OPTION is (a) Weak electrolyte Easy EXPLANATION: Pure water is a weak electrolyte. It DISSOCIATES to form hydrogen IONS and hydroxyl ions.

Discussion

80.	In recent liquid membrane electrodes, the porous liquid membrane is replaced with which of the following?(a) Polyvinyl chloride(b) Polyacryl chloride(c) Polyester membrane(d) Polyacryl amideThe question was posed to me in a job interview.This intriguing question comes from Ion Selective Electrodes-Principle and Types in division pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The correct answer is (a) POLYVINYL chloride Explanation: In RECENT liquid MEMBRANE electrodes, the porous liquid membrane is replaced with polyvinyl chloride membrane. The measured POTENTIAL is a direct measure of the CONCENTRATION of specific ion.

Discussion

81.	Which of the following is not the characteristic of ion selective electrodes?(a) Simple to use(b) Inexpensive(c) Narrow concentration range(d) Operates in wide range of temperatureI got this question in an interview for internship.The question is from Ion Selective Electrodes-Principle and Types in division pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Right option is (C) Narrow CONCENTRATION range To explain I would SAY: Ion SELECTIVE electrodes have a wide concentration range. It is highly selective to a particular ion.

Discussion

82.	Which of the following materials are used as a gel to which biocatalytic membrane is fixed in ammonia selective electrode?(a) Urea(b) Urease(c) Acrylamide(d) PolyacrylamideThis question was addressed to me at a job interview.Query is from Special Designs of Ion Selective Electrodes topic in chapter pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Correct option is (C) ACRYLAMIDE Easy explanation: The material USED as a gel to which biocatalytic membrane is fixed in ammonia selective electrode is acrylamide. This is ATTACHED to the ion selective electrode directly.

Discussion

83.	An example of biosensor, urea electrode makes use of which of the following electrodes?(a) Carbon dioxide electrode(b) Ammonia electrode(c) Fluoride electrode(d) Ammonium electrodeI got this question in final exam.My question comes from Biosensors topic in chapter pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Right option is (d) Ammonium electrode The best I can EXPLAIN: An example of biosensor, urea electrode MAKES USE of the ammonium electrode. A urease MEMBRANE is ALSO present.

Discussion

84.	While using reference electrodes, the internal liquid level should always be kept above that of the sample solution.(a) True(b) FalseThe question was asked by my school principal while I was bunking the class.Enquiry is from Secondary Reference Electrodes in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The correct option is (a) True To explain I would say: While USING reference electrodes, the internal LIQUID level should always be KEPT above that of the sample solution. This is done to prevent contamination of the electrolyte solution.

Discussion

85.	In fluoride ion electrode, the potential corresponding to level of the fluoride ion is described by which of the following equations when E is the measured electrode potential, Eo is the reference potential and A is the level of fluoride ions in solution?(a) E=Eo+0.0591 log A(b) E=Eo-0.0591 log A(c) E=Eo+0.0896 log A(d) E=Eo-0.0896 log AThis question was posed to me in an online quiz.My question is from Ammonia and Fluoride Electrode in division pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The CORRECT ANSWER is (b) E=Eo-0.0591 log A Easiest explanation: In fluoride ion electrode, the potential CORRESPONDING to LEVEL of the fluoride ion is described by the equation, E=Eo-0.0591 log A. A is the activity or effective concentration of fluoride ions.

Discussion

86.	The gel used in combination electrodes does not have which of the following characteristic?(a) Non-toxic(b) USP grade(c) Inorganic material(d) PolyacrylamideThe question was posed to me in unit test.My question is from Combination Electrode in division pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The CORRECT option is (c) Inorganic material Explanation: The gel USED in COMBINATION electrodes is organic. It can also be MADE of polyacrylamide.

Discussion

87.	The electrodes used in pH measurement have which of the following internal resistances?(a) Very low resistance(b) Moderate resistance(c) Very high resistance(d) No resistanceThe question was asked in unit test.Origin of the question is pH Meters topic in division pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The correct answer is (c) Very HIGH resistance For explanation: The electrodes USED in pH measurement have very high internal resistance. It is of the order of 1000M ohm.

Discussion

88.	Which of the following is used in potassium electrode in liquid membrane electrodes?(a) Ionomycin(b) Valinomycin(c) Nonactin(d) GramicidinI got this question in quiz.Enquiry is from Ion Selective Electrodes-Principle and Types in chapter pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Right answer is (b) Valinomycin The best I can explain: Valinomycin is USED in potassium ELECTRODE in liquid MEMBRANE ELECTRODES. It is a doughnut shaped electron rich pocket.

Discussion

89.	The timing for a microprocessor and for all signals is generated by the CPU clock.(a) True(b) FalseThis question was posed to me during an online interview.My doubt is from Ion Analyser topic in chapter pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Right answer is (a) True For explanation I would say: The timing for a MICROPROCESSOR and for all signals is GENERATED by the CPU clock. A CRYSTAL MAY be present to provide clock signals.

Discussion

90.	The response time of the biocatalytic membrane electrode is poor when used with complex organic molecules.(a) True(b) FalseI got this question by my college professor while I was bunking the class.Origin of the question is Special Designs of Ion Selective Electrodes in division pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The correct option is (b) False The best explanation: The response time of the biocatalytic MEMBRANE ELECTRODE is GOOD even when used with complex organic MOLECULES. But, the membrane is costly.

Discussion

91.	Which of the following is the value of hydroxyl ion concentration of pure water?(a) 1×10^7 moles/litre(b) 1×10^5 moles/litre(c) 1×10^6 moles/litre(d) 1×10^8 moles/litreThe question was asked during a job interview.Asked question is from pH Measurement and Types topic in portion pH Meters and Ion Analysers of Analytical Instrumentation
Answer» CORRECT OPTION is (a) 1×10^7 moles/litre Explanation: The hydroxyl ion concentration of PURE water is 1×10^7 moles/litre. It can be REPRESENTED as [OH-]=1×10^7 moles/litre.

Discussion

92.	Given below is the diagram of glass electrode. Identify the unmarked component.(a) Platinum leads(b) Silver wire coated with silver chloride(c) Copper wire(d) Platinum reference electrodeThis question was addressed to me in an international level competition.This question is from Hydrogen and Glass Electrodes topic in division pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Right ANSWER is (B) Silver WIRE coated with silver chloride Best explanation: The unmarked component is silver wire coated with silver chloride. It FORMS the inner reference electrode.

Discussion

93.	Which of the following is known as calomel?(a) Silver chloride(b) Mercury chloride(c) Potassium chloride(d) Mercury sulphateThis question was posed to me in class test.Asked question is from Secondary Reference Electrodes topic in portion pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The correct OPTION is (b) Mercury chloride Easy explanation: Mercury chloride is known as calomel. The most important GENERAL PURPOSE secondary electrode is calomel electrode.

Discussion

94.	Which of the following is not the characteristics of silver/silver chloride electrode?(a) These electrodes have good electrical and chemical stability(b) It can be used in temperatures greater than 600oC(c) It can be used in places or solutions that have strong reducing agents(d) It should not be used in solutions that contain proteins, sulphide or bromideI had been asked this question in a national level competition.The query is from Secondary Reference Electrodes topic in chapter pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The correct option is (c) It can be USED in places or solutions that have STRONG reducing agents Easy explanation: The silver/silver chloride electrode cannot be used in places or solutions that have strong reducing agents. They will REDUCE the silver ions to silver METAL.

Discussion

95.	pH meters can be considered as voltage sources with which of the following internal resistances?(a) Very low resistance(b) Moderate resistance(c) Very high resistance(d) No resistanceI got this question in an interview for internship.The query is from pH Meters topic in chapter pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The correct choice is (C) Very high resistance For EXPLANATION I would say: pH METERS can be considered as voltage sources with very high internal resistance. In order to eliminate errors, no CURRENT should flow from the source.

Discussion

96.	In combination electrode, which of the following electrodes are built together?(a) Primary electrode, secondary reference electrode(b) Primary reference electrode, glass electrode(c) Glass electrode, secondary reference electrode(d) Glass electrode with another glass electrodeThe question was asked during an online interview.My query is from Combination Electrode topic in portion pH Meters and Ion Analysers of Analytical Instrumentation
Answer» RIGHT option is (C) GLASS ELECTRODE, secondary reference electrode To elaborate: In combination electrode, glass electrode and secondary reference electrode are BUILT together. Internal reference electrode is identical with an external reference electrode.

Discussion

97.	Which of the following can be used to provide automatic temperature compensation?(a) Proper insulation(b) Calibration for different temperatures(c) Thermistor(d) ThermometerI had been asked this question in examination.I'm obligated to ask this question of pH Meters topic in division pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Right choice is (c) Thermistor For explanation I would SAY: To PROVIDE automatic temperature compensation, thermistors must be used. As the temperature of the SOLUTION CHANGES, the circuit constants are altered ACCORDINGLY.

Discussion

98.	Ion selective electrode are unaffected by colour or turbidity of the solution.(a) True(b) FalseThe question was posed to me by my college director while I was bunking the class.Asked question is from Ion Selective Electrodes-Principle and Types in division pH Meters and Ion Analysers of Analytical Instrumentation
Answer» CORRECT answer is (a) True To explain I would say: Ion SELECTIVE electrode are unaffected by colour or TURBIDITY of the SOLUTION. It operates in wide range of temperature.

Discussion

99.	Which of the following is the only operator entry required in PC-based ion analysers?(a) Hardware set-up(b) Signal measurement(c) Calibration(d) Sample calculationThe question was asked during an interview for a job.My doubt is from Ion Analyser topic in chapter pH Meters and Ion Analysers of Analytical Instrumentation
Answer» The CORRECT option is (c) Calibration The explanation is: Calibration is the only operator entry required in PC-based ion ANALYSERS. The operator has to enter the concentration of calibration STANDARDS.

Discussion

100.	Nanoscopic optical biosensors have fast response time but the sensitivity is reduced.(a) True(b) FalseThis question was addressed to me in an online interview.I'm obligated to ask this question of Biosensors in section pH Meters and Ion Analysers of Analytical Instrumentation
Answer» Correct option is (b) False For EXPLANATION: NANOSCOPIC optical biosensors have a fast response. They also have excellent BIOCHEMICAL sensitivity.

Discussion

Explore topic-wise InterviewSolutions in .

Calomel electrode can behave as which of the following components?(a) Anode only(b) Cathode only(c) Anode or cathode(d) Salt bridgeThis question was posed to me in class test.My enquiry is from Secondary Reference Electrodes topic in chapter pH Meters and Ion Analysers of Analytical Instrumentation

If an instrument fails to balance at zero, it is most likely that the electrodes are defective.(a) True(b) FalseI had been asked this question in an interview for internship.The origin of the question is pH Meters in chapter pH Meters and Ion Analysers of Analytical Instrumentation

Given below is the block diagram of digital pH meter. Identify the unmarked component.(a) Filter(b) Buffer(c) A/D converter(d) D/A converterThis question was posed to me in an interview for job.Question is from pH Meters topic in portion pH Meters and Ion Analysers of Analytical Instrumentation

Given below is the diagram of biosensor. Identify the unmarked component.(a) Microprocessor(b) Filter(c) Transducer(d) A/D converterI got this question during an internship interview.Query is from Biosensors topic in division pH Meters and Ion Analysers of Analytical Instrumentation

The dilution of solution must not reduce the level of ammonia below _________(a) 10^-2 M(b) 10^-5 M(c) 10^-8 M(d) 10^-9 MThe question was posed to me in semester exam.Enquiry is from Ammonia and Fluoride Electrode topic in section pH Meters and Ion Analysers of Analytical Instrumentation

Which of the following is used in potassium electrode in liquid membrane electrodes?(a) Ionomycin(b) Valinomycin(c) Nonactin(d) GramicidinI got this question in quiz.Enquiry is from Ion Selective Electrodes-Principle and Types in chapter pH Meters and Ion Analysers of Analytical Instrumentation

The timing for a microprocessor and for all signals is generated by the CPU clock.(a) True(b) FalseThis question was posed to me during an online interview.My doubt is from Ion Analyser topic in chapter pH Meters and Ion Analysers of Analytical Instrumentation

Which of the following is known as calomel?(a) Silver chloride(b) Mercury chloride(c) Potassium chloride(d) Mercury sulphateThis question was posed to me in class test.Asked question is from Secondary Reference Electrodes topic in portion pH Meters and Ion Analysers of Analytical Instrumentation

Nanoscopic optical biosensors have fast response time but the sensitivity is reduced.(a) True(b) FalseThis question was addressed to me in an online interview.I'm obligated to ask this question of Biosensors in section pH Meters and Ion Analysers of Analytical Instrumentation