FT IR Spectroscopy
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 these

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FT IR Spectroscopy
What does the Michelson interferometer do?

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

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FT IR Spectroscopy
Why is it advantageous to record many FID signals from the same sample and then add them together?

None of these
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

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FT IR Spectroscopy
When radiation energy is absorbed by a spin 1/2 nucleus in a magnetic field, what happens?

The angle of precession flips so that the magnetic moment of the nucleus opposes the applied field
The processional frequency of the nucleus increases
None of these
The nucleus spins faster

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FT IR Spectroscopy
In FT-NMR, how are nuclei excited?

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

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