Analytical Instrumentation MCQ

Analytical Instrumentation  MCQ

1. Lambert’s law states that the intensity of light decreases with respect to __________
a) Concentration
b) Distance
c) Composition
d) Volume
Answer: Distance

2. Beer’s law states that the intensity of light decreases with respect to ___________
a) Concentration
b) Distance
c) Composition
d) Volume
Answer: Concentration

3. Which of the following detectors does not require a battery and is also known as barrier layer cell?
a) Photomultiplier tube
b) Photovoltaic cell
c) Photoemissive tubes
d) Photo reflector
Answer: Photovoltaic cell

4. Which of the following is not a type of Spectroscopy?
a) Gamma ray
b) X ray
c) Nuclear magnetic resonance
d) Sound
Answer: Sound

5. How is Tungsten Halogen lamp differs from normal Tungsten filament lamp used in absorption spectroscopy?
a) It has a tungsten filament and is filled with inert gas
b) Iodine is added to normal filling gas
c) Iodine is coated on tungsten filament
d) Iodine is added to inert gas
Answer: Iodine is added to normal filling gas

6. Which of the following could be used as the layer of dielectric in interference filters used in Absorption Spectroscopy?
a) Graphite
b) MgF2
c) Fe
d) AgNO3
Answer: MgF2

7. How does continuous wedge filter differ from normal interference filter used in absorption spectroscopy?
a) It permits continuous selection of different wavelength
b) It allows a narrow band of wavelengths to pass
c) It has two semi-transparent layers of silver
d) Space layer is made of a substance having low refractive index
Answer: It permits continuous selection of different wavelength

8. How can stability of radiation be achieved in incandescent or discharge source used in Absorption Spectroscopy?
a) Using filters
b) Using monochromators
c) Using slits
d) By controlling the source voltage
Answer: By controlling the source voltage

9. Which of the following is false about the wavelengths of electromagnetic radiation?
a) Radiation with short wavelengths have high energies
b) Energy does not depend on wavelength
c) Radiation with long wavelengths have low energies
d) Energy depends on wavelength
Answer: Energy does not depend on wavelength

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

11. To tolerate high operating temperatures, which of the following has to be done in incandescent or tungsten filament lamps?
a) Alloys must be used
b) Nitrogen be used instead of inert gas
c) Envelope is fabricated with quartz
d) Envelope is fabricated with copper
Answer: Envelope is fabricated with quartz

12. Which type of Quantum Transition takes place in Ultra Violet and Visible spectroscopy?
a) Rotation of molecules
b) Nuclear
c) Bonding electrons
d) Spin of nuclei in a magnetic field
Answer: Bonding electrons

13. Which of the following is not a property or parameter of electromagnetic radiation?
a) Wavelength
b) Voltage
c) Wave number
d) Amplitude
Answer: Voltage

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

15. Beer Lambert’s law gives the relation between which of the following?
a) Reflected radiation and concentration
b) Scattered radiation and concentration
c) Energy absorption and concentration
d) Energy absorption and reflected radiation
Answer: Energy absorption and concentration

16. How is the wave number of electromagnetic radiation related to wavelength?
a) It is the reciprocal of wavelength
b) It is directly proportional to wavelength
c) It is not related to wavelength
d) It is equal to wavelength
Answer: It is the reciprocal of wavelength

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

18. Transmittance is given as T = P/Po. If Po is the power incident on the sample, what does P represent?
a) Radiant power transmitted by the sample
b) Radiant power absorbed by the sample
c) Sum of powers absorbed and scattered
d) Sum of powers transmitted and reflected
Answer: Radiant power transmitted by the sample

19. 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?
a) Intensity
b) Transmittance
c) Absorptivity
d) Admittance
Answer: Absorptivity

20. In which of the following ways, absorption is related to transmittance?
a) Absorption is the logarithm of transmittance
b) Absorption is the reciprocal of transmittance
c) Absorption is the negative logarithm of transmittance
d) Absorption is a multiple of transmittance
Answer: Absorption is the negative logarithm of transmittance

21. Which of the following is not true about Absorption spectroscopy?
a) It involves transmission
b) Scattering is kept minimum
c) Reflection is kept maximum
d) Intensity of radiation leaving the substance is an indication of a concentration
Answer: Reflection is kept maximum

22. Which of the following detectors is used to detect light intensities which are very weak?
a) Photomultiplier tube
b) Photovoltaic cell
c) Photoemissive tubes
d) Photo reflector
Answer: Photomultiplier tube

23. Which of the following is the wavelength of microwave radiation?
a) 10 – 780nm
b) 0.78 – 30┬Ám
c) 0.6 – 10 m
d) 0.75 – 3.75 mm
Answer: 0.75 – 3.75 mm

24. Spectroscopy deals with interaction of electromagnetic radiation with matter. What is the speed of this radiation in vacuum in m/s?
a) 6 x 108
b) 5 x 108
c) 7 x 108
d) 3 x 108
Answer: 3 x 108

25. What is the unit of absorbance which can be derived from Beer Lambert’s law?
a) L mol-1 cm-1
b) L gm-1 cm-1
c) Cm
d) No unit
Answer: No unit

26. Which of the following is the wavenumber of UV and Visible radiation?
a) 1 x 106 to 1.3 x 104 m-1
b) 1 x 106 to 1.3 x 104 m
c) 13 – 27 m-1
d) 1 x 106 to 1.3 x 104 m2
Answer: 1 x 106 to 1.3 x 104 m-1

27. What is the unit of molar absorptivity or absorptivity which is used to determine absorbance A in Beer Lambert’s formula?
a) L mol-1 cm-1
b) L gm-1 cm-1
c) Cm
d) No unit
Answer: L mol-1 cm-1

28. Velocity of electromagnetic radiation is more in a vacuum than in any medium.
a) True
b) False
Answer: True

29. Electromagnetic radiation can travel through a vacuum.
a) True
b) False
Answer: True

30. Beer’s law states that the intensity of light decreases with respect to Concentration
a) True
b) False
Answer: True

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