🧪 Analytical instruments MCQ Quiz Hub

1. Which type of Quantum Transition takes place in Ultra Violet and Visible spectroscopy?
Rotation of molecules
Nuclear
Bonding electrons
Spin of nuclei in a magnetic field

2. Which of the following is not a property or parameter of electromagnetic radiation?
Wavelength
Voltage
Wave number
Amplitude

3. Which of the following is not a type of Spectroscopy?
Gamma ray
X ray
Nuclear magnetic resonance
Sound

4. Electromagnetic radiation can travel through a vacuum.
True
False
all of the above
None of the mentioned

5. Which of the following is false about the wavelengths of electromagnetic radiation?
Radiation with short wavelengths have high energies
Energy does not depend on wavelength
Radiation with long wavelengths have low energies
Energy depends on wavelength

6. Which of the following is the wavelength of microwave radiation?
10 – 780nm
0.78 – 30µm
0.6 – 10 m
0.75 – 3.75 mm

7. How is the wave number of electromagnetic radiation related to wavelength?
It is the reciprocal of wavelength
It is directly proportional to wavelength
It is not related to wavelength
It is equal to wavelength

8. Which of the following is the wavenumber of UV and Visible radiation?
1 x 106 to 1.3 x 104 m-1
1 x 106 to 1.3 x 104 m
13 – 27 m-1
1 x 106 to 1.3 x 104 m2

9. Velocity of electromagnetic radiation is more in a vacuum than in any medium.
True
False
all of the above
None of the mentioned

10. Beer Lambert’s law gives the relation between which of the following?
Reflected radiation and concentration
Scattered radiation and concentration
Energy absorption and concentration
Energy absorption and reflected radiation

11. In which of the following ways, absorption is related to transmittance?
Absorption is the logarithm of transmittance
Absorption is the reciprocal of transmittance
Absorption is the negative logarithm of transmittance
Absorption is a multiple of transmittance

12. Which of the following is not a limitation of Beer Lambert’s law, which gives the relation between absorption, thickness and concentration?
Concentration must be lower
Radiation must have higher bandwidth
Radiation source must be monochromatic
Does not consider factors other than thickness and concentration that affect absorbance

13. Beer’s law states that the intensity of light decreases with respect to ______
Concentration
Distance
Composition
Volume

14. Lambert’s law states that the intensity of light decreases with respect to ______
Concentration
Distance
Composition
Volume

15. 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?
Intensity
Transmittance
Absorptivity
Admittance

16. Which of the following is not true about Absorption spectroscopy?
It involves transmission
Scattering is kept minimum
Reflection is kept maximum
Intensity of radiation leaving the substance is an indication of a concentration

17. Transmittance is given as T = P/Po. If Po is the power incident on the sample, what does P represent?
Radiant power transmitted by the sample
Radiant power absorbed by the sample
Sum of powers absorbed and scattered
Sum of powers transmitted and reflected

18. What is the unit of absorbance which can be derived from Beer Lambert’s law?
L mol-1 cm-1
L gm-1 cm-1
Cm
No unit

19. What is the unit of molar absorptivity or absorptivity which is used to determine absorbance A in Beer Lambert’s formula?
L mol-1 cm-1
L gm-1 cm-1
Cm
No unit

20. Which of the following detectors does not require a battery and is also known as barrier layer cell?
Photomultiplier tube
Photovoltaic cell
Photoemissive tubes
Photo reflector

21. Which of the following detectors is used to detect light intensities which are very weak?
Photomultiplier tube
Photomultiplier tube
Photoemissive tubes
Photo reflector

22. How is Tungsten Halogen lamp differs from normal Tungsten filament lamp used in absorption spectroscopy?
It has a tungsten filament and is filled with inert gas
It has a tungsten filament and is filled with inert gas
Iodine is coated on tungsten filament
Iodine is added to inert gas

23. Instead of glass filters, why gelatin filters could not be used for a long period while both are Absorption filters?
Gelatin tends to evaporate and hence they deteriorate
Gelatin is affected by humidity in the environment
They deteriorate due to absorption of heat leading to changes in gelatin
Gelation is affected by temperature in the environment

24. Gelation is affected by temperature in the environment
It permits continuous selection of different wavelength
It allows a narrow band of wavelengths to pass
It has two semi-transparent layers of silver
Space layer is made of a substance having low refractive index

25. Which of the following could be used as the layer of dielectric in interference filters used in Absorption Spectroscopy?
Graphite
MgF2
Fe
AgNO3

26. How can stability of radiation be achieved in incandescent or discharge source used in Absorption Spectroscopy?
Using filters
Using monochromators
Using slits
By controlling the source voltage

27. To tolerate high operating temperatures, which of the following has to be done in incandescent or tungsten filament lamps?
Alloys must be used
Nitrogen be used instead of inert gas
Envelope is fabricated with quartz
Envelope is fabricated with copper

28. Which of the following is not a reason for laser not being generally used as a source of radiation for UV, Visible Spectroscopy?
High cost
Limited range of wavelength
Less intensity
Complex to work with

29. Which of the following statements is false about single beam absorption instruments?
Tungsten bulb is used as a source
Beam splitter is used to get parallel beam
Test tube is used as sample holder
Photovoltaic cell as detector

30. Which of the following statement is false about double beam absorption instruments?
It is similar to single beam instruments except two beams are present
Tungsten bulb is used as a source
Reference beam must have a higher intensity than sample beam
Both the beams after they pass through respective samples are compared

31. Which of the following is not an application of colorimeter?
Paints
Inks
Cosmetics
Composition detection

32. In photometers, the readings of the specimen are initially obtained in the form of which of the following parameters?
Transmittance
Absorption
Wavelengths
Volume

33. Colorimeters are used in applications where great accuracy is required.
True
FALSE
all of the above
None of the mentioned

34. Which of the following is the purpose of balance indicator in double beam photometer or colorimeter?
Selects a particular wavelength
Splits the wavelength selected into two equal beams
Detects and indicates the amount of light falling on it
Indicates the difference between the output of two photometers

35. Which of the following is the purpose of the beam splitter in double beam photometer or colorimeter?
Splits beam into two equal intensity beams
Splits beam into two equal intensity beams
Splits beam in such a way that a reference beam has higher intensity
Merge two equal intensity beams into single beam

36. Which of the following is a source used in spectroscopy?
LASER
Tube light
Sodium vapour lamp
Tungsten lamp

37. Which of the following is not a source used in Mid Infrared Spectrophotometer?
Nernst glower
High pressure mercury arc lamp
Globar
Nichrome wire

38. Which of the following is the wave number of near infrared spectrometer?
4000 – 200 cm-1
200 – 10 cm-1
12500 – 4000 cm-1
50 – 1000 cm-1

39. Which of the following options are correct in terms of wavelength for the different types of IR spectrometer?
Near IR: 0.8 – 2.5 mm
Mid IR: 0.8 – 2.5 mm
Far IR: 2.5 – 50 mm
Mid IR: 50 – 100 mm

40. Which of the following is not a composition of Nernst glower or Nernst filament?
Oxides of Zirconium
Oxides of Barium
Oxides of Yitrium
Oxides of Thorium

41. What is the composition of Globar rod which is used as a source in Mid IR spectroscopy?
Silicon carbide
Silver chloride
Silicon dioxide
Silver carbide

42. Bolometer, a type of detector, is also known as _____
Resistance temperature detector (RTD)
Thermistor
Thermocouple
Golay cell

43. Which of the following is not a technique for preparing solid samples in IR spectroscopy?
Solids run in solution
Mull technique
Solid films
Thin films

44. Which of the following is not used as pyroelectric material used in pyroelectric transducers in Infrared spectroscopy?
Triglycine Sulphate
Deutrated Triglycine Sulphate
Some Polymers
Tetraglycine sulphate

45. Which of the following is the principle of Golay cell which is used as a detector in IR spectroscopy?
Expansion of gas upon heating
Increase in resistance due to an increase in temperature and vice versa
Temperature difference gives rise to a potential difference in the material
Decrease in resistance due to an increase in temperature

46. 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?
Pressed pellet
Mull technique
Solid films
Solids run in solution

47. Which of the following is not true about Fourier Transform Infrared (FTIR) spectrometer?
It is of non-dispersive type
It is useful where repetitive analysis is required
Size has been reduced over the years
Size has increased over the years

48. 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.
Mylar
Silicon carbide
Ferrous oxide
Silver chloride

49. Which of the following is not the function of the drive mechanism in Fourier Transform Infrared Spectrophotometer?
Movement of mirror to obtain a satisfactory interferogram
Acquire a good interferogram pattern
Allow 50% of the beam to pass
Keep the speed of the moving mirror constant

50. 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?
Less accuracy
Slower response
Less precision
Less sensitivity