Questions and answers for exam Preparation

MCQs

Total Questions : 18 | Page 1 of 2 pages

Question 1. Why is it advantageous to record many FID signals from the same sample and then add them together?

To ensure that all target nuclei in the sample have been excited
To remove inaccuracies caused by fluctuations in the applied magnetic field
To increase sensitivity
None of the above

Discuss Question

Answer: Option C. -> To increase sensitivity

Question 2. What is the name given to the relaxation process due to an interaction between an excited nucleus and the magnetic fields caused by nuclei in molecules moving around in the sample?

Spin - lattice relaxation
Spin - spin relaxation
Spin - spin - spin relaxation
None of these

Discuss Question

Answer: Option A. -> Spin - lattice relaxation

Question 3. What is meant by rotating frame of reference?

That the sample is spun rapidly in the applied field
If the laboratory itself is imagined to be rotated at the Larmor frequency, viewing that individual magnetic moment vectors are fixed in space
That the detector rotates around the sample
None of the above

Discuss Question

Answer: Option B. -> If the laboratory itself is imagined to be rotated at the Larmor frequency, viewing that individual magnetic moment vectors are fixed in space

Question 4. Cytochrome C has an isoelectric pH of

8.5
10.05
7.5
11.05

Discuss Question

Answer: Option B. -> 10.05

Question 5. Which of the following is the basis of first dimension of separation for two-dimensional electrophoresis?

Molecular mass
Solubility
Isoelectric point
Folding

Discuss Question

Answer: Option C. -> Isoelectric point

Question 6.
The sequence of amino acids in proteins can be determined by means of

identification of the -NH2 terminal amino acids
identification of the -COOH terminal amino acids
partial cleavage of the original polypeptide into smaller polypeptides
all of the above

Discuss Question

Answer: Option D. -> all of the above

Question 7. In FT-NMR, how are nuclei excited?

By radio-frequency radiation whose frequency is swept across a predetermined range
By an intense pulse of radiation which contains a wide range of frequencies
By an intense pressure
None of the above

Discuss Question

Answer: Option A. -> By radio-frequency radiation whose frequency is swept across a predetermined range

Question 8. What does the Michelson interferometer do?

Split a polychromatic beam of radiation into its component wavelengths
Selectively filter certain wavelengths from a beam of I.R. radiation
Modulate the I.R. signal at a lower frequency, so that it can be observed by a detector
none of the above

Discuss Question

Answer: Option C. -> Modulate the I.R. signal at a lower frequency, so that it can be observed by a detector

Question 9. In scanning electron microscopy