MRI PHYSICS FUNDAMENTALS EXAM LATEST 2026
UPDATE 100 QUESTIONS AND DETAILED VERIFIED
ANSWERS FROM ACTUAL EXAMS TEST GRADE A+
1. What is the primary magnetic field in MRI called?
A. RF field
B. Gradient field
C. Main field
D. Secondary field
Answer: C. Main field
The main magnetic field (B0) is the strong, static field that aligns hydrogen nuclei.
2. The unit used to measure magnetic field strength is:
A. Hertz
B. Tesla
C. Joules
D. Watts
Answer: B. Tesla
Magnetic field strength in MRI is measured in Tesla (T).
3. Larmor frequency is directly proportional to:
A. RF pulse duration
B. Magnetic field strength
C. Gradient strength
D. Echo time
Answer: B. Magnetic field strength
The Larmor equation shows frequency increases with magnetic field strength.
,4. Which nucleus is most commonly imaged in MRI?
A. Carbon
B. Oxygen
C. Hydrogen
D. Nitrogen
Answer: C. Hydrogen
Hydrogen has a high abundance and strong MR signal.
5. Precession refers to:
A. Random motion of nuclei
B. Alignment of spins
C. Wobbling motion around magnetic field
D. RF excitation
Answer: C. Wobbling motion around magnetic field
Precession is the circular motion of nuclei around the magnetic field axis.
6. T1 relaxation represents:
A. Loss of transverse magnetization
B. Recovery of longitudinal magnetization
C. RF pulse duration
D. Gradient switching
Answer: B. Recovery of longitudinal magnetization
T1 describes realignment of spins with the main magnetic field.
7. T2 relaxation describes:
A. Recovery of longitudinal magnetization
B. Loss of transverse coherence
C. RF signal production
D. Magnetic field strength
, Answer: B. Loss of transverse coherence
T2 decay reflects dephasing of spins in the transverse plane.
8. Which factor affects signal-to-noise ratio (SNR)?
A. Field strength
B. Voxel size
C. Number of averages
D. All of the above
Answer: D. All of the above
All listed factors influence SNR.
9. Increasing slice thickness will:
A. Decrease SNR
B. Increase SNR
C. Decrease resolution
D. Both B and C
Answer: D. Both B and C
Thicker slices increase SNR but reduce spatial resolution.
10. What is resonance in MRI?
A. Alignment of protons
B. RF pulse matching Larmor frequency
C. Gradient activation
D. Signal reception
Answer: B. RF pulse matching Larmor frequency
Resonance occurs when RF energy matches the natural frequency of protons.
Questions 11–20: Image Weighting & Parameters
UPDATE 100 QUESTIONS AND DETAILED VERIFIED
ANSWERS FROM ACTUAL EXAMS TEST GRADE A+
1. What is the primary magnetic field in MRI called?
A. RF field
B. Gradient field
C. Main field
D. Secondary field
Answer: C. Main field
The main magnetic field (B0) is the strong, static field that aligns hydrogen nuclei.
2. The unit used to measure magnetic field strength is:
A. Hertz
B. Tesla
C. Joules
D. Watts
Answer: B. Tesla
Magnetic field strength in MRI is measured in Tesla (T).
3. Larmor frequency is directly proportional to:
A. RF pulse duration
B. Magnetic field strength
C. Gradient strength
D. Echo time
Answer: B. Magnetic field strength
The Larmor equation shows frequency increases with magnetic field strength.
,4. Which nucleus is most commonly imaged in MRI?
A. Carbon
B. Oxygen
C. Hydrogen
D. Nitrogen
Answer: C. Hydrogen
Hydrogen has a high abundance and strong MR signal.
5. Precession refers to:
A. Random motion of nuclei
B. Alignment of spins
C. Wobbling motion around magnetic field
D. RF excitation
Answer: C. Wobbling motion around magnetic field
Precession is the circular motion of nuclei around the magnetic field axis.
6. T1 relaxation represents:
A. Loss of transverse magnetization
B. Recovery of longitudinal magnetization
C. RF pulse duration
D. Gradient switching
Answer: B. Recovery of longitudinal magnetization
T1 describes realignment of spins with the main magnetic field.
7. T2 relaxation describes:
A. Recovery of longitudinal magnetization
B. Loss of transverse coherence
C. RF signal production
D. Magnetic field strength
, Answer: B. Loss of transverse coherence
T2 decay reflects dephasing of spins in the transverse plane.
8. Which factor affects signal-to-noise ratio (SNR)?
A. Field strength
B. Voxel size
C. Number of averages
D. All of the above
Answer: D. All of the above
All listed factors influence SNR.
9. Increasing slice thickness will:
A. Decrease SNR
B. Increase SNR
C. Decrease resolution
D. Both B and C
Answer: D. Both B and C
Thicker slices increase SNR but reduce spatial resolution.
10. What is resonance in MRI?
A. Alignment of protons
B. RF pulse matching Larmor frequency
C. Gradient activation
D. Signal reception
Answer: B. RF pulse matching Larmor frequency
Resonance occurs when RF energy matches the natural frequency of protons.
Questions 11–20: Image Weighting & Parameters
