ABSORPTION INSTRUMENTATION AND BLOCK DIAGRAM REPRESENTATION

Question 1

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 1

b) Photovoltaic cell

Question 2

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 2

a) Photomultiplier tube

Question 3

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 3

b) Iodine is added to normal filling gas

Question 4

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 4

c) They deteriorate due to absorption of heat leading to changes in gelatin

Question 5

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 5

a) It permits continuous selection of different wavelength

Question 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 6

b) MgF2

Question 7

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 7

d) By controlling the source voltage

Question 8

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 8

c) Envelope is fabricated with quartz

Question 9

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 9

c) Less intensity