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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.

1.

Which of the following is the function of the throttling device?(a) Filtering(b) Maintains pH of a water(c) Purifies water(d) Maintains constant flow rateI have been asked this question in final exam.The origin of the question is Dissolved Oxygen Analyser topic in division Dissolved Component Analysers of Analytical Instrumentation

Answer» CORRECT option is (d) Maintains CONSTANT flow rate

To explain: The function of the throttling DEVICE is to MAINTAIN a constant flow rate. The water then PASSES into the condenser.
2.

Which of the following indicate leakages in a condenser?(a) The concentration of sodium in steam and condensate are very high(b) The concentration of sodium in steam and condensate are very low(c) The concentration of sodium in steam and condensate are equal(d) The concentration of sodium in steam and condensate are not equalThis question was addressed to me in examination.My doubt is from Sodium Analyser in chapter Dissolved Component Analysers of Analytical Instrumentation

Answer»

Right choice is (d) The CONCENTRATION of SODIUM in steam and condensate are not equal

The EXPLANATION: If the concentration of sodium in steam and condensate are not equal, it MEANS that leakage is present in the condenser. If the VALUES are equal, then it means that no leakage is present.

3.

The output from both the detectors is given to which of the following devices?(a) Filters(b) Microprocessor(c) Recorder(d) Differential AmplifierI had been asked this question by my school teacher while I was bunking the class.The origin of the question is Silica Analyser topic in portion Dissolved Component Analysers of Analytical Instrumentation

Answer»

The correct CHOICE is (d) Differential AMPLIFIER

Explanation: The output from both the DETECTORS is GIVEN to the differential amplifier. The amplified signal is read through a DISPLAY.

4.

How will the photodetector output be if silica content is high in a solution?(a) The output will be high(b) The output will be low(c) The output will be zero(d) Output cannot be determinedI got this question by my school teacher while I was bunking the class.This intriguing question comes from Silica Analyser in division Dissolved Component Analysers of Analytical Instrumentation

Answer»

The correct choice is (b) The output will be LOW

The explanation is: If silica content is high in a SOLUTION, the DETECTOR output will be low. This is because more light is absorbed by the solution and less AMOUNT of light is transmitted.

5.

How does solubility of oxygen in water change with respect to temperature?(a) It decreases with increase in temperature(b) It increases with increase in temperature(c) It decreases with decrease in temperature(d) It does not depend on temperatureI had been asked this question by my college director while I was bunking the class.This intriguing question comes from Dissolved Oxygen Analyser in portion Dissolved Component Analysers of Analytical Instrumentation

Answer»

Correct option is (a) It DECREASES with increase in TEMPERATURE

Best explanation: SOLUBILITY of oxygen in water decreases with increase in temperature. Dissolved oxygen is the MEASURE of ABILITY of water to sustain aquatic life.

6.

During the first sequence of the process, sample is added at the last.(a) True(b) FalseThe question was posed to me in an internship interview.I need to ask this question from Silica Analyser topic in division Dissolved Component Analysers of Analytical Instrumentation

Answer»

The CORRECT OPTION is (a) True

For explanation I would SAY: During the first sequence of the PROCESS, sample is added at the last. During the second sequence, all the solutions are added in a normal manner.

7.

Which of the following bridges are used in dissolved oxygen analyser?(a) Kelvin’s bridge(b) Wheatstone bridge(c) Schering’s bridge(d) Anderson’s bridgeThe question was asked in an online interview.The doubt is from Dissolved Oxygen Analyser in section Dissolved Component Analysers of Analytical Instrumentation

Answer»

The correct answer is (b) Wheatstone BRIDGE

Easy explanation: Wheatstone bridge is used in dissolved oxygen analyser. INITIALLY, the bridge is in a BALANCED condition.

8.

Oxygen content can be controlled by adding which of the following materials with water?(a) Acidic solution(b) Basic solution(c) Iodine(d) HydrazineThe question was posed to me during a job interview.The doubt is from Dissolved Oxygen Analyser topic in portion Dissolved Component Analysers of Analytical Instrumentation

Answer»

Right option is (d) Hydrazine

The best explanation: OXYGEN content can be CONTROLLED by ADDING hydrazine with water. It is important to MAINTAIN dissolved oxygen content in boilers to reduce CORROSION.

9.

The output of the electrode in sodium analyser is proportional to which of the following parameters?(a) Activity(b) Concentration(c) Negative logarithm of sodium ion concentration(d) Logarithm of sodium ion concentrationThis question was posed to me by my college professor while I was bunking the class.I'd like to ask this question from Sodium Analyser in chapter Dissolved Component Analysers of Analytical Instrumentation

Answer» RIGHT option is (d) Logarithm of sodium ion concentration

The explanation is: The OUTPUT of the electrode in sodium analyser is PROPORTIONAL to the logarithm of sodium ion concentration. The VALUE is recorded and indicated.
10.

In dissolved oxygen analyser, the electrometer consists of which of the following solutions?(a) Calcium hydroxide solution(b) Magnesium hydroxide solution(c) Potassium hydroxide solution(d) Calcium oxide solutionI had been asked this question in a job interview.Asked question is from Dissolved Oxygen Analyser topic in portion Dissolved Component Analysers of Analytical Instrumentation

Answer»

Correct answer is (C) Potassium hydroxide SOLUTION

For EXPLANATION I would say: In dissolved oxygen analyser, the electrometer consists of potassium hydroxide solution. It PRODUCES HYDROGEN due to the electrolysis process.

11.

Which of the following represent the concentration of a solution?(a) Only free ions(b) Only bound ions(c) Free ions and bound ions(d) Either free ions or bound ionsThis question was addressed to me in class test.My query is from Sodium Analyser in section Dissolved Component Analysers of Analytical Instrumentation

Answer»

The CORRECT ANSWER is (C) Free ions and bound ions

Easy explanation: Concentration refers to the sum of free ions and bound ions. ACTIVITY refers only to free ions.

12.

Normally, electrodes measure which of the following parameters?(a) Activity(b) Activity co-efficient(c) Blank constant(d) Ionic co-efficientI have been asked this question in exam.This intriguing question comes from Sodium Analyser in portion Dissolved Component Analysers of Analytical Instrumentation

Answer»

The CORRECT CHOICE is (a) Activity

To elaborate: NORMALLY, electrodes measure activity of the ION. It is a measure of free IONS in the solution.

13.

Which of the following are added for pH adjustment in sodium analyser?(a) Acidic solution(b) Basic solution(c) Hydrazine(d) Ammonia bufferThis question was addressed to me by my school teacher while I was bunking the class.The query is from Sodium Analyser topic in portion Dissolved Component Analysers of Analytical Instrumentation

Answer» CORRECT option is (d) Ammonia buffer

To explain: Ammonia buffer is added for PH adjustment in SODIUM analyser. This is added to the reference and SAMPLE solutions.
14.

Which of the following are used to free bound ions or liberate bound ions?(a) Colouring agents(b) Ammonia Buffer(c) Reagents(d) Iodine solutionI had been asked this question at a job interview.This is a very interesting question from Sodium Analyser in section Dissolved Component Analysers of Analytical Instrumentation

Answer» RIGHT choice is (c) Reagents

To EXPLAIN: Reagents are used to free bound ions or liberate bound ions. The ADDITION of reagent prevents unwanted ions from entering into the MEASUREMENT.
15.

Which of the following principles are used in silica analyser?(a) Amperometric principle(b) Colorimetric principle(c) Coulometric principle(d) Magnetic principleThis question was posed to me in an international level competition.This question is from Silica Analyser topic in chapter Dissolved Component Analysers of Analytical Instrumentation

Answer»

Right OPTION is (b) Colorimetric principle

Explanation: The principle USED in SILICA analyser is colorimetric principle. The COLOUR of the final solution is measured.

16.

Cleaning process gives accuracy and long life.(a) True(b) FalseThis question was addressed to me in class test.Origin of the question is Sodium Analyser topic in section Dissolved Component Analysers of Analytical Instrumentation

Answer»

Right answer is (a) True

Explanation: Cleaning process GIVES accuracy and LONG LIFE. SPRAY NOZZLES can be used to clean the electrodes.

17.

In dissolved oxygen analyser, normally more than one condenser is used.(a) True(b) FalseI have been asked this question in final exam.This key question is from Dissolved Oxygen Analyser in division Dissolved Component Analysers of Analytical Instrumentation

Answer»

The correct ANSWER is (a) True

Easy explanation: In dissolved oxygen analyser, normally more than one CONDENSER is USED. The CONDENSERS are PRESENT in the condenser section.

18.

Presence of sodium sulphate in water causes corrosion in boilers.(a) True(b) FalseI have been asked this question at a job interview.The above asked question is from Sodium Analyser in chapter Dissolved Component Analysers of Analytical Instrumentation

Answer»

The correct choice is (a) True

Best explanation: Presence of sodium sulphate in WATER causes corrosion in BOILERS. Sodium HYDROXIDE and sodium chloride SALTS also CAUSE corrosion.

19.

Which of the following is not added to the sample during analysis during silica analysis?(a) Ammonium Molybdate(b) Sulphuric acid(c) Reducing solution(d) Iodine solutionThis question was posed to me in an international level competition.The question is from Silica Analyser topic in section Dissolved Component Analysers of Analytical Instrumentation

Answer»

Correct option is (d) Iodine solution

Explanation: Iodine solution is not ADDED to the sample during analysis. Ammonium molybdate, SULPHURIC acid and REDUCING solution are added to the sample.

20.

If the differential amplifier gives zero as output then it infers which of the following (Reference output is given to the positive terminal and sample output is given to the negative terminal)?(a) The concentration of silica in sample and reference solution is equal(b) The concentration of silica in a reference solution is more than that in the sample solution(c) The concentration of silica in sample solution is more than that in the reference solution(d) Further processing is required to come to any conclusionThe question was asked in homework.Asked question is from Silica Analyser topic in portion Dissolved Component Analysers of Analytical Instrumentation

Answer»

Right option is (a) The concentration of silica in SAMPLE and reference solution is EQUAL

The explanation is: If the differential amplifier gives ZERO as output then, it means that the concentration of silica in sample and reference solution is equal. It means that the photodetectors’ output is equal.

21.

If the differential amplifier gives a positive output then it infers which of the following (Reference output is given to the positive terminal and sample output is given to the negative terminal)?(a) The concentration of silica in sample and reference solution is equal(b) The concentration of silica in a reference solution is more than that in the sample solution(c) The concentration of silica in sample solution is more than that in the reference solution(d) Further processing is required to come to any conclusionThe question was asked at a job interview.This interesting question is from Silica Analyser topic in chapter Dissolved Component Analysers of Analytical Instrumentation

Answer»

Right option is (C) The concentration of silica in sample solution is more than that in the reference solution

Easy explanation: If the differential amplifier GIVES a positive OUTPUT then, it means that the concentration of silica in sample solution is more than that in the reference solution. It means that the photodetectors’ output is not EQUAL.

22.

What will be the final colour of the solution obtained during silica analysis?(a) Pink(b) Red(c) Blue(d) YellowThis question was addressed to me during an interview for a job.This interesting question is from Silica Analyser topic in chapter Dissolved Component Analysers of Analytical Instrumentation

Answer»

Correct OPTION is (c) Blue

Easy explanation: This METHOD works on the principle of MOLYBDENUM blue method. HENCE, the COLOUR of the final solution will be blue.

23.

Blank use compensates for the effect of temperature variation.(a) True(b) FalseThis question was addressed to me during a job interview.This key question is from Silica Analyser topic in section Dissolved Component Analysers of Analytical Instrumentation

Answer»

Right CHOICE is (a) True

Explanation: Blank USE compensates for the effect of temperature VARIATION. It also compensates for various other variables such as ageing of lamps and coloration of the SAMPLE.

24.

If the differential amplifier gives a negative output then it infers which of the following (Reference output is given to the positive terminal and sample output is given to the negative terminal)?(a) The concentration of silica in sample and reference solution is equal(b) The concentration of silica in a reference solution is more than that in the sample solution(c) The concentration of silica in sample solution is more than that in the reference solution(d) Further processing is required to come to any conclusionThe question was posed to me in examination.I need to ask this question from Silica Analyser in section Dissolved Component Analysers of Analytical Instrumentation

Answer» CORRECT option is (b) The CONCENTRATION of silica in a reference solution is more than that in the sample solution

To explain: If the differential amplifier gives a NEGATIVE output then, it MEANS that the concentration of silica in a reference solution is more than that in the sample solution. It means that the photodetector’s output is not equal.
25.

In which part of the apparatus is the reference and ion selective electrodes placed?(a) Head tank(b) Flow cell(c) Reservoir(d) Solenoid valveThe question was posed to me during an interview for a job.I need to ask this question from Sodium Analyser topic in section Dissolved Component Analysers of Analytical Instrumentation

Answer»

Right CHOICE is (b) Flow cell

Explanation: The reference and ion SELECTIVE electrodes are PLACED in the flow cell. SAMPLE is MAINTAINED in the constant head tank.

26.

Which of the following section plays a major role in maintaining the accuracy of the dissolved oxygen analyser?(a) Analysing section(b) Inlet section(c) Transmitting section(d) Condensing sectionI have been asked this question in homework.My question comes from Dissolved Oxygen Analyser in division Dissolved Component Analysers of Analytical Instrumentation

Answer»

Correct choice is (c) TRANSMITTING section

To elaborate: Transmitting section plays a major ROLE in maintaining the ACCURACY of the dissolved OXYGEN analyser. It is the section after the ANALYSING section.

27.

Which of the following statements are true?(a) More light is absorbed if the silica content is high in a solution(b) More light is transmitted if the silica content is high in a solution(c) Less light is absorbed if the silica content is high in a solution(d) More light is absorbed if the silica content is low in a solutionThis question was addressed to me in class test.This intriguing question originated from Silica Analyser in division Dissolved Component Analysers of Analytical Instrumentation

Answer»

The CORRECT option is (a) More light is ABSORBED if the silica CONTENT is high in a solution

The explanation: More amount of light is absorbed if the silica content is high in a solution. Less amount of light is TRANSMITTED if the silica content is high in a solution.

28.

Sodium selective electrode provides a good response in measurement when the pH is above which of the following values?(a) 2(b) 3(c) 5(d) 10The question was posed to me during an interview for a job.I want to ask this question from Sodium Analyser in chapter Dissolved Component Analysers of Analytical Instrumentation

Answer» CORRECT answer is (d) 10

For explanation: Sodium selective ELECTRODE provides a good response in measurement when the pH of the solution is above 10. Hence, the BUFFER solution is USED.
29.

The water to be analysed flows into the condenser through which of the following components?(a) Filter(b) Semi-permeable membrane(c) Throttling device(d) Platinum filamentI had been asked this question in a national level competition.My query is from Dissolved Oxygen Analyser in division Dissolved Component Analysers of Analytical Instrumentation

Answer»

Correct choice is (C) THROTTLING device

To explain: The water to be analysed FLOWS into the CONDENSER through a throttling device. It is COOLED in the condenser.

30.

Which of the following transducers must be used for dissolved oxygen analyser?(a) Potentiometric(b) Polarographic(c) Ion-selective electrode(d) Optical transducerI got this question by my school teacher while I was bunking the class.My question is based upon Dissolved Oxygen Analyser topic in section Dissolved Component Analysers of Analytical Instrumentation

Answer»

Right choice is (b) POLAROGRAPHIC

The explanation: Polarographic transducer must be used for dissolved oxygen analyser. Dissolved oxygen is the MEASURE of ABILITY of water to SUSTAIN aquatic life.

31.

Which of the following detectors are used in silica analyser?(a) Photovoltaic cell(b) Photo multiplier(c) Photo emissive tubes(d) Flame emission detectorThe question was posed to me in semester exam.This key question is from Silica Analyser topic in division Dissolved Component Analysers of Analytical Instrumentation

Answer»

Correct CHOICE is (a) Photovoltaic CELL

For EXPLANATION I would say: Photovoltaic cell is used as a DETECTOR in silica analyser. This detector does not need a BATTERY for operation.

32.

The dissolved oxygen analyser is based on which of the following meters?(a) Amperometer(b) Katharometer(c) pH meter(d) VoltmeterThis question was posed to me in an interview.This intriguing question originated from Dissolved Oxygen Analyser in section Dissolved Component Analysers of Analytical Instrumentation

Answer»

Correct choice is (B) Katharometer

Explanation: The dissolved OXYGEN ANALYSER is based on katharometer. It works on the PRINCIPLE of thermal conductivity detector.