MRI PHYSICS FINAL PAPER 2026 FULL
QUESTIONS AND CORRECT ANSWERS
◉What will changes in nuclei have on the gyromatic ratio?. Answer:
a. Will have a different preccesional frequency
b. The frequency of the RF pulse must be different
◉Einstein's theory of conservation:. Answer: a. The amount of
energy in the universe is constant
b. Energy cannot be created or destroyed
c. Energy can only be transformed from one source to another
◉Resonance. Answer: occurs when an nuclei is exposed to an
oscillating perturbatrion that is close to its own natural frequency.
gets excited, and becomes a spin down nuclei
◉Results of resonance. Answer: creates a flip angle.
causes the nuclei to angle to Bo.
◉Steps of resonance. Answer: 1. nuclei is exposed to to peturbation
of a simmular freq.
, 2. nuclei gains energy
3. nuclei moves towards transverse path
◉Flip Angle. Answer: i. The angle to which the nmv moves out of
alignment.
ii. The amount of the flip angle depends on the streinght and
duration of the RF pulse
◉Phase. Answer: the position of each magenetic momenet on the
precessional path around Bo.
◉Why is the maximum MR signal generated @90 degrees to Bo?.
Answer: Two things occur with the induction of the RF pulse
a. Increase of energy of the H atoms which move them towards the
transverse plane
b. H atom precession in unison
◉MR signal. Answer: b. The MR signal is produced when coherent
(inphase) magnetization cuts across the coil.
c. magnetic field fluctuations inside the coil that induce an electrical
voltage in the coil.
d. This voltage is the MR signal.
QUESTIONS AND CORRECT ANSWERS
◉What will changes in nuclei have on the gyromatic ratio?. Answer:
a. Will have a different preccesional frequency
b. The frequency of the RF pulse must be different
◉Einstein's theory of conservation:. Answer: a. The amount of
energy in the universe is constant
b. Energy cannot be created or destroyed
c. Energy can only be transformed from one source to another
◉Resonance. Answer: occurs when an nuclei is exposed to an
oscillating perturbatrion that is close to its own natural frequency.
gets excited, and becomes a spin down nuclei
◉Results of resonance. Answer: creates a flip angle.
causes the nuclei to angle to Bo.
◉Steps of resonance. Answer: 1. nuclei is exposed to to peturbation
of a simmular freq.
, 2. nuclei gains energy
3. nuclei moves towards transverse path
◉Flip Angle. Answer: i. The angle to which the nmv moves out of
alignment.
ii. The amount of the flip angle depends on the streinght and
duration of the RF pulse
◉Phase. Answer: the position of each magenetic momenet on the
precessional path around Bo.
◉Why is the maximum MR signal generated @90 degrees to Bo?.
Answer: Two things occur with the induction of the RF pulse
a. Increase of energy of the H atoms which move them towards the
transverse plane
b. H atom precession in unison
◉MR signal. Answer: b. The MR signal is produced when coherent
(inphase) magnetization cuts across the coil.
c. magnetic field fluctuations inside the coil that induce an electrical
voltage in the coil.
d. This voltage is the MR signal.
