Name____________________________

1. Nuclear Overhauser Effect, n.o.e., is:

a) the name given to the reason magnetic moment preccess in a magnetic field.

b) the effective coupling between one nuclei and a neighboring nuclei

c) the enhanced intensity one gets in a C-13 spectrum when the H attached to it is decoupled.

d) the effect one gets by giving a nuclei a 180 degree pulse.

2. The maximum NMR signal is obtained by a single pulse of ________ degrees.

a) 45 b) 90 c) 180 d) 360

3. A fast relaxation time (a low value of T2) will lead to a) narrow peaks b) broad peaks

c) low intensity peaks d) high intensity peaks.

4. The signal to noise ratio is 50:1 after 16 transients. What would the signal to noise ratio be after just one pulse?

a) 4.2:1 b) 200:1 c) 12.5:1 d) 800:1 e) 80:1

5. All other things being equal, by what factor would you multiply NT in order to get the same signal to noise ratio on a sample that is 1/10 as concentrated as the original.

a) .01 b) .1 c) 1 d) 10 e) 100

6. The 90o pulse width for an instrument is 12 microseconds. If the a 24 microsecond pulse is given on the x axis, where will the magnetic vector of the nucleus (initially on the z axis) end up immediately after the pulse?.

a) -z axis b) -x axis c) -y axis d) half way between the x and the y axis. e) +z axis.

Name____________________________

1. Nuclear Overhauser Effect, n.o.e., is:

a) the name given to the reason magnetic moment preccess in a magnetic field.

b) the effective coupling between one nuclei and a neighboring nuclei

c) the enhanced intensity one gets in a C-13 spectrum when the H attached to it is decoupled.

d) the effect one gets by giving a nuclei a 180 degree pulse.

2. The maximum NMR signal is obtained by a single pulse of ________ degrees.

a) 45 b) 90 c) 180 d) 360

3. A fast relaxation time (a low value of T2) will lead to a) narrow peaks b) broad peaks

c) low intensity peaks d) high intensity peaks.

4. The signal to noise ratio is 50:1 after 16 transients. What would the signal to noise ratio be after just one pulse?

a) 4.2:1 b) 200:1 c) 12.5:1 d) 800:1 e) 80:1

5. All other things being equal, by what factor would you multiply NT in order to get the same signal to noise ratio on a sample that is 1/10 as concentrated as the original.

a) .01 b) .1 c) 1 d) 10 e) 100

6. The 90o pulse width for an instrument is 12 microseconds. If the a 24 microsecond pulse is given on the x axis, where will the magnetic vector of the nucleus (initially on the z axis) end up immediately after the pulse?.

a) -z axis b) -x axis c) -y axis d) half way between the x and the y axis. e) +z axis.