R4RIN – MCQs, Mock Tests | Analytical instruments Analytical Instrumentation MCQ Question Set 4

Which of the following UV absorbance detectors provide a real time spectrum of the component of interest?

1. Continuous wavelength detector
2. Variable wavelength detector
3. Scanning wavelength detector
4. Fixed wavelength detector

✅ Correct Answer: 3

Fluorescence detection is less selective than absorption detection.

1. True
2. False
3. all of the above
4. None of the mentioned

✅ Correct Answer: 2

Which of the following detectors depend on Snell’s law at the interface between the cell wall and the flowing liquid to deflect the light beam?

1. Electrochemical detectors
2. Fluorescence detectors
3. Refractive index detectors
4. Thermal conductivity detectors

✅ Correct Answer: 3

Refractive index detectors used in liquid chromatography are not based on which of the following processes?

1. Interference
2. Refraction
3. Reflection
4. Absorption

✅ Correct Answer: 4

Which of the following detectors can be used for detection of amino acids in protein hydrolyzates by introducing the reagent dansylchloride in the sample?

1. Electrochemical detectors
2. Fluorescence detectors
3. Refractive index detectors
4. Thermal conductivity detectors

✅ Correct Answer: 2

The reference cell is packed with which of the following in the Adsorption detector used in liquid chromatography?

1. Inactive glass beads
2. Porous glass beads
3. Alumina
4. Silica

✅ Correct Answer: 1

Which of the following detectors used in liquid chromatography is also called micro-adsorption detector?

1. Electrochemical detectors
2. Fluorescence detectors
3. Refractive index detectors
4. Thermal detectors

✅ Correct Answer: 4

In UV-Visible detectors, the cells are not made of which of the following materials?

1. Quartz
2. Teflon
3. Silica
4. KELF

✅ Correct Answer: 3

Which of the following is not a feature of refractive index type detectors?

1. Higher potential sensitivity
2. Low cost
3. High volume flow rates
4. Easy cell accessibility

✅ Correct Answer: 3

Which of the following detectors can detect almost any component?

1. Combining two UV detectors
2. Combining RI and UV detectors
3. Mass detector
4. Laser-based detectors

✅ Correct Answer: 2

Chromatography is a physical method that is used to separate and analyse _______

1. Simple mixtures
2. Complex mixtures
3. Viscous mixtures
4. Metals

✅ Correct Answer: 2

In chromatography, the stationary phase can be _____supported on a solid.

1. Solid or liquid
2. Liquid or gas
3. Solid only
4. Liquid only

✅ Correct Answer: 1

Which among the following gases have diamagnetic property (ability to be repelled by magnetic fields)?

1. Oxygen
2. Nitrogen
3. Nitrogen dioxide
4. Nitric oxide

✅ Correct Answer: 2

Which of the following gases have paramagnetic property (ability to get attracted to a magnetic field)?

1. Nitric oxide
2. Hydrogen
3. Helium
4. Nitrogen

✅ Correct Answer: 1

The force produced during the operation of Paramagnetic oxygen analyzer is proportional to which of the following?

1. Magnetic susceptibility of sphere
2. Magnetic susceptibility of surrounding gas
3. Difference between magnetic susceptibility of sphere and magnetic field strength
4. Difference between magnetic susceptibility of sphere and that of surrounding gas

✅ Correct Answer: 4

In Paramagnetic oxygen analyzer, the expression for magnitude of force produced can be expressed as, F = C (K-KO), where K= magnetic susceptibility of surrounding gas and KO= magnetic susceptibility of sphere. C denotes which of the following?

1. Magnetic field strength
2. Magnetic gradient
3. Function of magnetic field strength and gradient
4. Magnetic flux

✅ Correct Answer: 3

In Paramagnetic oxygen analyzer, the electrostatic force that is exerted should have which of the following features?

1. It should be greater than the magnetic field and must be in the same direction
2. It should be equal to the magnetic field and must be in the same direction
3. It should be greater than the magnetic field and must be in the opposite direction
4. It should be equal to the magnetic field and must be in the opposite direction

✅ Correct Answer: 4

Which of the following is true about the two charged vanes that produce electric field in Paramagnetic oxygen analyzer?

1. Both the vanes should be at higher potential than the test body
2. Both the vanes should have the same potential as the test body
3. One vane should be at higher potential than the test body and the other vane should be at lower potential
4. Both the vanes should be at lower potential than the test body

✅ Correct Answer: 3

In Paramagnetic oxygen analyzer, when no oxygen is present the magnetic force balances torque of the fibre.

1. True
2. False
3. all of the above
4. None of the mentioned

✅ Correct Answer: 1

To improve paramagnetic oxygen analyzer, the quartz suspension must be replaced with which of the following?

1. Platinum-iridium
2. Phosphor-bronze
3. Gold-palladium
4. Antimony

✅ Correct Answer: 1

In the Beckman instrument, the flow rate recommended when the sample enters through a porous diffusion disc is which of the following?

1. 100-200 cc/min
2. 50-250 cc/min
3. 40-60 cc/min
4. 200-300 cc/min

✅ Correct Answer: 2

In the Beckman instrument, the flow rate recommended when the sample enters directly for rapid response is which of the following?

1. 100-200 cc/min
2. 50-250 cc/min
3. 40-60 cc/min
4. 200-300 cc/min

✅ Correct Answer: 3

Which of the following happens to the magnetic susceptibility of gases when the temperature changes?

1. It increases with increase in temperature
2. It decreases with increase in temperature
3. It remains constant with increase in temperature
4. It remains constant with decrease in temperature

✅ Correct Answer: 2

If the oxygen content is not greater than 21%, which of the following gases must be used to set the span point?

1. Oxygen
2. Dry air
3. Nitrogen
4. Hydrogen

✅ Correct Answer: 2

If the oxygen content is greater than 21%, which of the following gases must be used to set the span point?

1. Oxygen
2. Dry air
3. Nitrogen
4. Hydrogen

✅ Correct Answer: 1

Which of the following does not occur in Hartman and Braun oxygen analyzer based on the magnetic wind?

1. Oxygen is attracted to the magnetic field
2. Oxygen becomes less paramagnetic due to rise in temperature
3. Resistance change in a resistance connected to the Wheatstone bridge occur
4. Wheatstone Bridge becomes balanced due to temperature change

✅ Correct Answer: 4

Which of the following is not a cause of the error that could occur in Hartman and Braun oxygen analyzer based on the magnetic wind?

1. The filament temperature could be affected by changes in thermal conductivity of the carrier gas
2. Hydrocarbons in sample stream may react on the heated filaments
3. Gravitation chimney flow effect lead to errors when cross tube is horizontal
4. Combustible gases may react on the heated filaments

✅ Correct Answer: 3

Hydrocarbons need to be removed from the sample gas to avoid errors in Hartman and Braun oxygen analyzer.

1. True
2. False
3. all of the above
4. None of the mentioned

✅ Correct Answer: 1

Magnetic wind analyzers are also known as which of the following?

1. Thermo-magnetic analyzers
2. Electro-magnetic analyzers
3. Thermo-analytical analyzers
4. Hot wire analyzers

✅ Correct Answer: 1

In OXYMAT-M oxygen analyser which of the following is usually used as reference gas?

1. Hydrogen
2. Nitrogen
3. Helium
4. Ambient air

✅ Correct Answer: 4

Which of the following is used in magnetic wind instruments to determine the amount of oxygen?

1. Change in resistance
2. Change in capacitance
3. Change in inductance
4. Change in concentration

✅ Correct Answer: 1

Which of the following concepts are not used in magnetic wind instruments?

1. Change in resistance due to cooling by magnetic wind
2. Displacement of membrane by magnetised oxygen
3. Difference in pressure difference between two gases having varying concentration of oxygen
4. By measuring temperature using thermometer

✅ Correct Answer: 4

How are the hydrocarbons in the samples removed in magnetic wind instruments?

1. By using a cold trap
2. By using a filter
3. By using a semipermeable membrane
4. By using magnetic effect

✅ Correct Answer: 1

Which of the following bridges are used in magnetic wind instruments?

1. Wheatstone bridge
2. Kelvin’s bridge
3. Anderson’s bridge
4. Schering’s bridge

✅ Correct Answer: 1

The extremely high inertia of the thin membrane in the oxygen sensor allows it to rapidly attain equilibrium.

1. True
2. False
3. all of the above
4. None of the mentioned

✅ Correct Answer: 2

Nitrogen dioxide can be detected with a paramagnetic analyser.

1. True
2. False
3. all of the above
4. None of the mentioned

✅ Correct Answer: 1

Nitrogen oxide cannot be directly analysed using UV and Visible analyzers due to which of the following reasons?

1. Less accuracy
2. Very low range
3. It leads to contamination of the sample
4. It is transparent in UV visible regions

✅ Correct Answer: 4

How is NO converted to NO2 for analysis in UV and Visible analyzers?

1. Treating sample gas with pressurized oxygen
2. Treating sample gas with ozone
3. Treating sample gas with oxygen at low pressure
4. Treating sample gas with water at high pressure

✅ Correct Answer: 1

How is NO converted to NO2 for analysis in Chemiluminescent analyser?

1. Treating sample gas with pressurized oxygen
2. Treating sample gas with ozone
3. Treating sample gas with oxygen at low pressure
4. Treating sample gas with water at high pressure

✅ Correct Answer: 2

During analysis of NO2 using Chemiluminescent analyser, why is NO2 not made to react with ozone directly?

1. Less accuracy
2. It is a slow process
3. It leads to contamination of the sample
4. It does not produce luminescence

✅ Correct Answer: 2

The instruments based on chemiluminescence maintain linearity in which of the following ranges?

1. 1ppb to 100ppb
2. 100ppb to 1000ppb
3. 1ppb to 1000ppb
4. 100ppb to 1000ppb

✅ Correct Answer: 3

How can absorption be enhanced while determining NO concentration using CO laser?

1. By converting NO into NO2
2. By placing NO in a magnetic field
3. By using proper monochromators
4. By using choppers

✅ Correct Answer: 2

Which of the following detectors are generally used for detection in NO analysis using CO laser?

1. Photomultiplier tube
2. Photovoltaic cell
3. Liquid nitrogen cooled Ge-Au element
4. Photo emissive tube

✅ Correct Answer: 3

Which of the following analyzers are used to measure trace amounts of nitrogen oxides in the stratosphere?

1. Chemiluminescence
2. CO laser method
3. Laser opto-acoustic spectroscopy
4. Colorimetry

✅ Correct Answer: 3

A pink coloured dye complex is formed when air containing NO2 is passed in an absorbing solution consisting of __________ and diamine dissolved in the acetic acid medium.

1. Sulphuric acid
2. Sulphonyl
3. Sulphonic acid
4. Sulphanilic acid

✅ Correct Answer: 4

In Laser Opto-acoustic spectroscopy, the IR beam excites the molecules to higher states. In which of the following ways do the molecules return to the ground state?

1. Collisional de-excitation
2. Random de-excitation
3. By spontaneous emission
4. By stimulated emission

✅ Correct Answer: 1

To monitor oxides of nitrogen in stack effluents, the sample containing oxides of nitrogen is passed through a flask containing solution of H2O2 in sulphuric acid. Nitric acid is formed. The nitrate ions then react with phenol-disulphonic acid to produce blue colour.

1. True
2. False
3. all of the above
4. None of the mentioned

✅ Correct Answer: 2

Which of the following is not an advantage of electrochemical cells used for analysis of H2S?

1. Portable battery operated instrument
2. Pocket sized instrument
3. No pumps are needed
4. No interference from background gases

✅ Correct Answer: 4

Which of the following methods are mainly used in combustible gas detection equipment?

1. Lead acetate tape staining method
2. Solid state sensor
3. Gold film sensor
4. Electrochemical cells

✅ Correct Answer: 2

Which of the following is not an advantage of solid state sensor used for analysis of H2S?

1. No sampling system
2. It can be used in conditions involving vibration
3. It can be used in corrosive atmosphere
4. No interference from background gases

✅ Correct Answer: 4