CGSB NDT LEVEL 2 CERTIFICATION EXAM 2026 | ACCURATE
REAL EXAM QUESTIONS AND VERIFIED ANSWERS WITH
RATIONALES | EXPERT VERIFIED FOR GUARANTEED PASS |
LATEST UPDATE
SECTION A: ADVANCED NDT PRINCIPLES AND PHYSICS (Questions 1-30)
Question 1
Which of the following best describes the relationship between wavelength (λ),
frequency (f), and velocity (v) in ultrasonic testing?
A. v = f × λ
B. v = λ / f
C. f = v × λ
D. λ = v × f
Correct Answer: A
Rationale: The fundamental wave equation is v = f × λ. Velocity is constant for a
given material and mode. Higher frequency results in shorter wavelength, which
improves resolution but reduces penetration.
Question 2
What is the "critical angle" in ultrasonic testing?
A. The angle of incidence at which the refracted longitudinal wave angle equals
90°, resulting in no longitudinal wave in the second material
B. The angle at which total reflection occurs
C. The angle of the transducer wedge
D. The angle at which shear waves are generated
Correct Answer: A
Rationale: The first critical angle occurs when the refracted longitudinal wave is at
90° to the normal, meaning no longitudinal wave enters the second material. Only
1
,shear waves propagate. The second critical angle eliminates shear waves, leaving
only surface waves.
Question 3
According to Snell's Law, what determines the angle of refraction when an
ultrasonic wave passes from one medium to another?
A. The ratio of the velocities in the two media
B. The frequency of the wave
C. The amplitude of the wave
D. The density of the first medium only
Correct Answer: A
Rationale: Snell's Law states: (sin θ₁ / v₁) = (sin θ₂ / v₂). The refraction angle
depends on the ratio of velocities between the two materials. This is the basis for
angle-beam UT.
Question 4
In eddy current testing, what is the relationship between frequency, conductivity,
and permeability in determining skin depth?
A. Skin depth is inversely proportional to the square root of (frequency ×
conductivity × permeability)
B. Skin depth is directly proportional to frequency
C. Skin depth is independent of conductivity
D. Skin depth is inversely proportional to permeability
Correct Answer: A
Rationale: Skin depth (δ) = 1 / √(π × f × μ × σ). Higher frequency, permeability, or
conductivity results in shallower skin depth. This is why ET is a surface/near-
surface method.
Question 5
What is the "inverse square law" in radiography?
A. Intensity is inversely proportional to the square of the distance from the source
2
,B. Intensity is directly proportional to distance
C. Intensity is inversely proportional to distance
D. Intensity is independent of distance
Correct Answer: A
Rationale: The inverse square law states that radiation intensity (I) decreases with
the square of the distance (d): I₁ / I₂ = (d₂ / d₁)². This is critical for calculating
exposure times and safe working distances.
Question 6
What is "beam divergence" in UT?
A. The spreading of the ultrasonic beam as it travels through the material
B. The focusing of the beam
C. The attenuation of the beam
D. The reflection of the beam
Correct Answer: A
Rationale: Beam divergence (or beam spread) is the natural spreading of the
ultrasonic beam as it propagates. It is influenced by transducer diameter and
frequency. Smaller transducers and lower frequencies diverge more.
Question 7
What is the difference between "amplitude" and "intensity" in ultrasound?
A. Amplitude is the height of the wave; intensity is the power per unit area
(proportional to amplitude squared)
B. Amplitude is the power; intensity is the height
C. They are the same
D. Amplitude is measured in decibels; intensity is measured in hertz
Correct Answer: A
Rationale: Amplitude is the peak displacement of the wave (voltage). Intensity is
the energy per unit area and is proportional to the square of the amplitude. Both
are used to characterize signals.
3
, Question 8
What is the "near field" length (N) of a transducer determined by?
A. N = D² / (4λ)
B. N = D² × (4λ)
C. N = D / (2λ)
D. N = λ / D²
Correct Answer: A
Rationale: The near field length (N) = D² / (4λ), where D is the transducer
diameter and λ is the wavelength. The near field is the region of complex
interference; flaw sizing is best performed in the far field.
Question 9
What is the effect of increasing the frequency of an eddy current test?
A. It decreases skin depth and increases sensitivity to surface defects
B. It increases skin depth
C. It has no effect on skin depth
D. It reduces sensitivity to surface defects
Correct Answer: A
Rationale: Higher frequency reduces skin depth (less penetration) but improves
the resolution of surface defects because the eddy currents are more
concentrated near the surface. This is the classic trade-off in ET.
Question 10
What does "acoustic impedance" (Z) represent in UT?
A. Z = ρ × v (density × velocity)
B. Z = ρ / v
C. Z = v / ρ
D. Z = ρ + v
Correct Answer: A
4
REAL EXAM QUESTIONS AND VERIFIED ANSWERS WITH
RATIONALES | EXPERT VERIFIED FOR GUARANTEED PASS |
LATEST UPDATE
SECTION A: ADVANCED NDT PRINCIPLES AND PHYSICS (Questions 1-30)
Question 1
Which of the following best describes the relationship between wavelength (λ),
frequency (f), and velocity (v) in ultrasonic testing?
A. v = f × λ
B. v = λ / f
C. f = v × λ
D. λ = v × f
Correct Answer: A
Rationale: The fundamental wave equation is v = f × λ. Velocity is constant for a
given material and mode. Higher frequency results in shorter wavelength, which
improves resolution but reduces penetration.
Question 2
What is the "critical angle" in ultrasonic testing?
A. The angle of incidence at which the refracted longitudinal wave angle equals
90°, resulting in no longitudinal wave in the second material
B. The angle at which total reflection occurs
C. The angle of the transducer wedge
D. The angle at which shear waves are generated
Correct Answer: A
Rationale: The first critical angle occurs when the refracted longitudinal wave is at
90° to the normal, meaning no longitudinal wave enters the second material. Only
1
,shear waves propagate. The second critical angle eliminates shear waves, leaving
only surface waves.
Question 3
According to Snell's Law, what determines the angle of refraction when an
ultrasonic wave passes from one medium to another?
A. The ratio of the velocities in the two media
B. The frequency of the wave
C. The amplitude of the wave
D. The density of the first medium only
Correct Answer: A
Rationale: Snell's Law states: (sin θ₁ / v₁) = (sin θ₂ / v₂). The refraction angle
depends on the ratio of velocities between the two materials. This is the basis for
angle-beam UT.
Question 4
In eddy current testing, what is the relationship between frequency, conductivity,
and permeability in determining skin depth?
A. Skin depth is inversely proportional to the square root of (frequency ×
conductivity × permeability)
B. Skin depth is directly proportional to frequency
C. Skin depth is independent of conductivity
D. Skin depth is inversely proportional to permeability
Correct Answer: A
Rationale: Skin depth (δ) = 1 / √(π × f × μ × σ). Higher frequency, permeability, or
conductivity results in shallower skin depth. This is why ET is a surface/near-
surface method.
Question 5
What is the "inverse square law" in radiography?
A. Intensity is inversely proportional to the square of the distance from the source
2
,B. Intensity is directly proportional to distance
C. Intensity is inversely proportional to distance
D. Intensity is independent of distance
Correct Answer: A
Rationale: The inverse square law states that radiation intensity (I) decreases with
the square of the distance (d): I₁ / I₂ = (d₂ / d₁)². This is critical for calculating
exposure times and safe working distances.
Question 6
What is "beam divergence" in UT?
A. The spreading of the ultrasonic beam as it travels through the material
B. The focusing of the beam
C. The attenuation of the beam
D. The reflection of the beam
Correct Answer: A
Rationale: Beam divergence (or beam spread) is the natural spreading of the
ultrasonic beam as it propagates. It is influenced by transducer diameter and
frequency. Smaller transducers and lower frequencies diverge more.
Question 7
What is the difference between "amplitude" and "intensity" in ultrasound?
A. Amplitude is the height of the wave; intensity is the power per unit area
(proportional to amplitude squared)
B. Amplitude is the power; intensity is the height
C. They are the same
D. Amplitude is measured in decibels; intensity is measured in hertz
Correct Answer: A
Rationale: Amplitude is the peak displacement of the wave (voltage). Intensity is
the energy per unit area and is proportional to the square of the amplitude. Both
are used to characterize signals.
3
, Question 8
What is the "near field" length (N) of a transducer determined by?
A. N = D² / (4λ)
B. N = D² × (4λ)
C. N = D / (2λ)
D. N = λ / D²
Correct Answer: A
Rationale: The near field length (N) = D² / (4λ), where D is the transducer
diameter and λ is the wavelength. The near field is the region of complex
interference; flaw sizing is best performed in the far field.
Question 9
What is the effect of increasing the frequency of an eddy current test?
A. It decreases skin depth and increases sensitivity to surface defects
B. It increases skin depth
C. It has no effect on skin depth
D. It reduces sensitivity to surface defects
Correct Answer: A
Rationale: Higher frequency reduces skin depth (less penetration) but improves
the resolution of surface defects because the eddy currents are more
concentrated near the surface. This is the classic trade-off in ET.
Question 10
What does "acoustic impedance" (Z) represent in UT?
A. Z = ρ × v (density × velocity)
B. Z = ρ / v
C. Z = v / ρ
D. Z = ρ + v
Correct Answer: A
4
