Questions and answers for exam Preparation

MCQs

Total Questions : 100 | Page 10 of 10 pages

Question 91. When would the recorder indicate a zero base line in analyzers based on gas density?

When the detector on the sample side is cooler than that on the reference side
When the detector on the reference side is cooler than that on the sample side
When flow is unbalanced
When both the detectors are equally cooled

Discuss Question

Answer: Option D. -> When both the detectors are equally cooled
Answer: (d).When both the detectors are equally cooled

Question 92. The use of thermistor eliminates the requirement for amplification.

True
False
May be True or False
Can't say

Discuss Question

Answer: Option A. -> True
Answer: (a).True

Question 93. Which of the following bridges are used in analyzers based on gas density?

Wheatstone bridge
Kelvin’s bridge
Anderson’s bridge
Schering’s bridge

Discuss Question

Answer: Option A. -> Wheatstone bridge
Answer: (a).Wheatstone bridge

Question 94. In analyzers based on gas density, the unbalance of the bridge is linearly proportional to which of the following?

Temperature of sample detector
Pressure at sample detector
Pressure difference between both the detectors
Gas-density difference between both the detectors

Discuss Question

Answer: Option D. -> Gas-density difference between both the detectors
Answer: (d).Gas-density difference between both the detectors

Question 95. In analyzers based on gas density, if the sample carries a gas having a higher density than the detector which of the following occurs?

It will cause a net downward flow
It will cause a net upward flow
It splits into two beams
There will be no difference in flow

Discuss Question

Answer: Option A. -> It will cause a net downward flow
Answer: (a).It will cause a net downward flow

Question 96. Which of the following detectors are generally used for detection in NO analysis using CO laser?

Photomultiplier tube
Photovoltaic cell
Liquid nitrogen cooled Ge-Au element
Photo emissive tube

Discuss Question

Answer: Option C. -> Liquid nitrogen cooled Ge-Au element
Answer: (c).Liquid nitrogen cooled Ge-Au element

Question 97. 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?

Collisional de-excitation
Random de-excitation
By spontaneous emission
By stimulated emission

Discuss Question

Answer: Option A. -> Collisional de-excitation
Answer: (a).Collisional de-excitation

Question 98. Which of the following analyzers are used to measure trace amounts of nitrogen oxides in the stratosphere?

Chemiluminescence
CO laser method
Laser opto-acoustic spectroscopy
Colorimetry

Discuss Question

Answer: Option C. -> Laser opto-acoustic spectroscopy
Answer: (c).Laser opto-acoustic spectroscopy

Question 99. 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.

Sulphuric acid
Sulphonyl
Sulphonic acid
Sulphanilic acid

Discuss Question

Answer: Option D. -> Sulphanilic acid
Answer: (d).Sulphanilic acid

Question 100. 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.