Olete.in – MCQs, Mock Tests & Government Job Prep | Analytical instruments Analytical Instrumentation MCQ Question Set 1

Which type of Quantum Transition takes place in Ultra Violet and Visible spectroscopy?

1. Rotation of molecules
2. Nuclear
3. Bonding electrons
4. Spin of nuclei in a magnetic field

✅ Correct Answer: 3

Which of the following is not a property or parameter of electromagnetic radiation?

1. Wavelength
2. Voltage
3. Wave number
4. Amplitude

✅ Correct Answer: 2

Which of the following is not a type of Spectroscopy?

1. Gamma ray
2. X ray
3. Nuclear magnetic resonance
4. Sound

✅ Correct Answer: 4

Electromagnetic radiation can travel through a vacuum.

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

✅ Correct Answer: 1

Which of the following is false about the wavelengths of electromagnetic radiation?

1. Radiation with short wavelengths have high energies
2. Energy does not depend on wavelength
3. Radiation with long wavelengths have low energies
4. Energy depends on wavelength

✅ Correct Answer: 2

Which of the following is the wavelength of microwave radiation?

1. 10 – 780nm
2. 0.78 – 30µm
3. 0.6 – 10 m
4. 0.75 – 3.75 mm

✅ Correct Answer: 4

How is the wave number of electromagnetic radiation related to wavelength?

1. It is the reciprocal of wavelength
2. It is directly proportional to wavelength
3. It is not related to wavelength
4. It is equal to wavelength

✅ Correct Answer: 1

Which of the following is the wavenumber of UV and Visible radiation?

1. 1 x 106 to 1.3 x 104 m-1
2. 1 x 106 to 1.3 x 104 m
3. 13 – 27 m-1
4. 1 x 106 to 1.3 x 104 m2

✅ Correct Answer: 1

Velocity of electromagnetic radiation is more in a vacuum than in any medium.

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

✅ Correct Answer: 1

Beer Lambert’s law gives the relation between which of the following?

1. Reflected radiation and concentration
2. Scattered radiation and concentration
3. Energy absorption and concentration
4. Energy absorption and reflected radiation

✅ Correct Answer: 3

In which of the following ways, absorption is related to transmittance?

1. Absorption is the logarithm of transmittance
2. Absorption is the reciprocal of transmittance
3. Absorption is the negative logarithm of transmittance
4. Absorption is a multiple of transmittance

✅ Correct Answer: 3

Which of the following is not a limitation of Beer Lambert’s law, which gives the relation between absorption, thickness and concentration?

1. Concentration must be lower
2. Radiation must have higher bandwidth
3. Radiation source must be monochromatic
4. Does not consider factors other than thickness and concentration that affect absorbance

✅ Correct Answer: 2

Beer’s law states that the intensity of light decreases with respect to ______

1. Concentration
2. Distance
3. Composition
4. Volume

✅ Correct Answer: 1

Lambert’s law states that the intensity of light decreases with respect to ______

1. Concentration
2. Distance
3. Composition
4. Volume

✅ Correct Answer: 2

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?

1. Intensity
2. Transmittance
3. Absorptivity
4. Admittance

✅ Correct Answer: 3

Which of the following is not true about Absorption spectroscopy?

1. It involves transmission
2. Scattering is kept minimum
3. Reflection is kept maximum
4. Intensity of radiation leaving the substance is an indication of a concentration

✅ Correct Answer: 3

Transmittance is given as T = P/Po. If Po is the power incident on the sample, what does P represent?

1. Radiant power transmitted by the sample
2. Radiant power absorbed by the sample
3. Sum of powers absorbed and scattered
4. Sum of powers transmitted and reflected

✅ Correct Answer: 1

What is the unit of absorbance which can be derived from Beer Lambert’s law?

1. L mol-1 cm-1
2. L gm-1 cm-1
3. Cm
4. No unit

✅ Correct Answer: 4

What is the unit of molar absorptivity or absorptivity which is used to determine absorbance A in Beer Lambert’s formula?

1. L mol-1 cm-1
2. L gm-1 cm-1
3. Cm
4. No unit

✅ Correct Answer: 1

Which of the following detectors does not require a battery and is also known as barrier layer cell?

1. Photomultiplier tube
2. Photovoltaic cell
3. Photoemissive tubes
4. Photo reflector

✅ Correct Answer: 2

Which of the following detectors is used to detect light intensities which are very weak?

1. Photomultiplier tube
2. Photomultiplier tube
3. Photoemissive tubes
4. Photo reflector

✅ Correct Answer: 1

How is Tungsten Halogen lamp differs from normal Tungsten filament lamp used in absorption spectroscopy?

1. It has a tungsten filament and is filled with inert gas
2. It has a tungsten filament and is filled with inert gas
3. Iodine is coated on tungsten filament
4. Iodine is added to inert gas

✅ Correct Answer: 2

Instead of glass filters, why gelatin filters could not be used for a long period while both are Absorption filters?

1. Gelatin tends to evaporate and hence they deteriorate
2. Gelatin is affected by humidity in the environment
3. They deteriorate due to absorption of heat leading to changes in gelatin
4. Gelation is affected by temperature in the environment

✅ Correct Answer: 3

Gelation is affected by temperature in the environment

1. It permits continuous selection of different wavelength
2. It allows a narrow band of wavelengths to pass
3. It has two semi-transparent layers of silver
4. Space layer is made of a substance having low refractive index

✅ Correct Answer: 1

Which of the following could be used as the layer of dielectric in interference filters used in Absorption Spectroscopy?

1. Graphite
2. MgF2
3. Fe
4. AgNO3

✅ Correct Answer: 2

How can stability of radiation be achieved in incandescent or discharge source used in Absorption Spectroscopy?

1. Using filters
2. Using monochromators
3. Using slits
4. By controlling the source voltage

✅ Correct Answer: 4

To tolerate high operating temperatures, which of the following has to be done in incandescent or tungsten filament lamps?

1. Alloys must be used
2. Nitrogen be used instead of inert gas
3. Envelope is fabricated with quartz
4. Envelope is fabricated with copper

✅ Correct Answer: 3

Which of the following is not a reason for laser not being generally used as a source of radiation for UV, Visible Spectroscopy?

1. High cost
2. Limited range of wavelength
3. Less intensity
4. Complex to work with

✅ Correct Answer: 3

Which of the following statements is false about single beam absorption instruments?

1. Tungsten bulb is used as a source
2. Beam splitter is used to get parallel beam
3. Test tube is used as sample holder
4. Photovoltaic cell as detector

✅ Correct Answer: 2

Which of the following statement is false about double beam absorption instruments?

1. It is similar to single beam instruments except two beams are present
2. Tungsten bulb is used as a source
3. Reference beam must have a higher intensity than sample beam
4. Both the beams after they pass through respective samples are compared

✅ Correct Answer: 3

Which of the following is not an application of colorimeter?

1. Paints
2. Inks
3. Cosmetics
4. Composition detection

✅ Correct Answer: 4

In photometers, the readings of the specimen are initially obtained in the form of which of the following parameters?

1. Transmittance
2. Absorption
3. Wavelengths
4. Volume

✅ Correct Answer: 1

Colorimeters are used in applications where great accuracy is required.

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

✅ Correct Answer: 2

Which of the following is the purpose of balance indicator in double beam photometer or colorimeter?

1. Selects a particular wavelength
2. Splits the wavelength selected into two equal beams
3. Detects and indicates the amount of light falling on it
4. Indicates the difference between the output of two photometers

✅ Correct Answer: 4

Which of the following is the purpose of the beam splitter in double beam photometer or colorimeter?

1. Splits beam into two equal intensity beams
2. Splits beam into two equal intensity beams
3. Splits beam in such a way that a reference beam has higher intensity
4. Merge two equal intensity beams into single beam

✅ Correct Answer: 1

Which of the following is a source used in spectroscopy?

1. LASER
2. Tube light
3. Sodium vapour lamp
4. Tungsten lamp

✅ Correct Answer: 4

Which of the following is not a source used in Mid Infrared Spectrophotometer?

1. Nernst glower
2. High pressure mercury arc lamp
3. Globar
4. Nichrome wire

✅ Correct Answer: 2

Which of the following is the wave number of near infrared spectrometer?

1. 4000 – 200 cm-1
2. 200 – 10 cm-1
3. 12500 – 4000 cm-1
4. 50 – 1000 cm-1

✅ Correct Answer: 3

Which of the following options are correct in terms of wavelength for the different types of IR spectrometer?

1. Near IR: 0.8 – 2.5 mm
2. Mid IR: 0.8 – 2.5 mm
3. Far IR: 2.5 – 50 mm
4. Mid IR: 50 – 100 mm

✅ Correct Answer: 1

Which of the following is not a composition of Nernst glower or Nernst filament?

1. Oxides of Zirconium
2. Oxides of Barium
3. Oxides of Yitrium
4. Oxides of Thorium

✅ Correct Answer: 2

What is the composition of Globar rod which is used as a source in Mid IR spectroscopy?

1. Silicon carbide
2. Silver chloride
3. Silicon dioxide
4. Silver carbide

✅ Correct Answer: 1

Bolometer, a type of detector, is also known as _____

1. Resistance temperature detector (RTD)
2. Thermistor
3. Thermocouple
4. Golay cell

✅ Correct Answer: 2

Which of the following is not a technique for preparing solid samples in IR spectroscopy?

1. Solids run in solution
2. Mull technique
3. Solid films
4. Thin films

✅ Correct Answer: 4

Which of the following is not used as pyroelectric material used in pyroelectric transducers in Infrared spectroscopy?

1. Triglycine Sulphate
2. Deutrated Triglycine Sulphate
3. Some Polymers
4. Tetraglycine sulphate

✅ Correct Answer: 4

Which of the following is the principle of Golay cell which is used as a detector in IR spectroscopy?

1. Expansion of gas upon heating
2. Increase in resistance due to an increase in temperature and vice versa
3. Temperature difference gives rise to a potential difference in the material
4. Decrease in resistance due to an increase in temperature

✅ Correct Answer: 1

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?

1. Pressed pellet
2. Mull technique
3. Solid films
4. Solids run in solution

✅ Correct Answer: 2

Which of the following is not true about Fourier Transform Infrared (FTIR) spectrometer?

1. It is of non-dispersive type
2. It is useful where repetitive analysis is required
3. Size has been reduced over the years
4. Size has increased over the years

✅ Correct Answer: 4

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.

1. Mylar
2. Silicon carbide
3. Ferrous oxide
4. Silver chloride

✅ Correct Answer: 1

Which of the following is not the function of the drive mechanism in Fourier Transform Infrared Spectrophotometer?

1. Movement of mirror to obtain a satisfactory interferogram
2. Acquire a good interferogram pattern
3. Allow 50% of the beam to pass
4. Keep the speed of the moving mirror constant

✅ Correct Answer: 3

Only pyroelectric transducer or pyroelectric crystals are used as detectors in Fourier Transform Infrared Spectrophotometer (FTIR). What is the main reason for other types of thermal detectors are not being used in FTIR spectrophotometer?

1. Less accuracy
2. Slower response
3. Less precision
4. Less sensitivity

✅ Correct Answer: 2