Questions and answers for exam Preparation

MCQs

Total Questions : 133 | Page 6 of 14 pages

Question 51. If to one pair of electrodes one potential with one sign is applied, which of the following is applied to the other pair of electrodes?

Same potential with same sign
Different potential with same sign
Different potential with different sign
Same potential with different sign

Discuss Question

Answer: Option D. -> Same potential with different sign
Answer: (d).Same potential with different sign

Question 52. In cases where differentiation is required between very similar substances, which of the following techniques making use of quadrupole principle is preferred?

Evaporation mass spectrometry
Pyrolysis mass spectrometry
Plasma mass spectrometry
Trapped ion mass spectrometry

Discuss Question

Answer: Option B. -> Pyrolysis mass spectrometry
Answer: (b).Pyrolysis mass spectrometry

Question 53. Which of the following is the heart of quadrupole instrument?

Electrodes
Choke
DC potential
Detector

Discuss Question

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

Question 54. Which of the following has to be done to increase the resolution of the quadrupole mass spectrometer?

Increasing distance between detector and reflectron
Increasing difference between the individual rf accelerating stages
Increasing the length of the drift tube
Increasing the rod length of the electrode

Discuss Question

Answer: Option D. -> Increasing the rod length of the electrode
Answer: (d).Increasing the rod length of the electrode

Question 55. Which of the following does not affect the resolution of the instrument?

Changing length of electrode
Changing slope of scan line
Quality of machining of the rods
Changing length of drift tube

Discuss Question

Answer: Option D. -> Changing length of drift tube
Answer: (d).Changing length of drift tube

Question 56. In pyrolysis spectrometry, heating is done until which of the following is reached?

Curie point
Boiling point
Until production of superheated vapour
Until 100°C

Discuss Question

Answer: Option A. -> Curie point
Answer: (a).Curie point

Question 57. Which of the following is used to cool the ion source?

Liquid sodium shield
Liquid nitrogen shield
Water
Freon

Discuss Question

Answer: Option B. -> Liquid nitrogen shield
Answer: (b).Liquid nitrogen shield

Question 58. In quadrupole mass spectrometer, the ratio u/v is mass dependent, where ‘u’ is the DC voltage and ‘v’ is the peak amplitude.

True
False
May be True or False
Can't say

Discuss Question

Answer: Option B. -> False
Answer: (b).False

Question 59. When a value of q is kept constant, the value of m/e is proportional to which of the following when ‘m’ is the mass number, ‘e’ is the electric charge, ‘u’ is the DC potential, ‘v’ is the peak amplitude and ‘f’ is the frequency?