Career upgrade: Learn practical AI skills for better jobs and higher pay.
Level up
PracticeVideosBlogFlashcardsEspañol
All Practice Exams

100+ Free ASNT NDT III RT Practice Questions

Pass your ASNT NDT Level III Radiographic Testing (RT) exam on the first try — instant access, no signup required.

✓ No registration✓ No credit card✓ No hidden fees✓ Start practicing immediately
Not publicly disclosed Pass Rate
100+ Questions
100% Free
1 / 100
Question 1
Score: 0/0

A 'shim' under an IQI per ASME Section V is used when:

A
B
C
D
to track
Same family resources

Explore More ASNT NDT Certifications

Continue into nearby exams from the same family. Each card keeps practice questions, study guides, flashcards, videos, and articles in one place.

ASNT NDT II

Practice Questions
1 blog

ASNT NDT Level III

Practice Questions
1 video1 blog

ASNT Industrial Radiography Radiation Safety Personnel (IRRSP)

Practice Questions

ASNT NDT Level III Basic

Practice Questions

ASNT NDT Level III Electromagnetic / Eddy Current Testing (ET)

Practice Questions

ASNT NDT Level III Infrared / Thermal Testing (IR)

Practice Questions

More From This Family

Videos and articles for deeper review.

VideoFREE ASNT NDT Level III Exam Guide 2026: Basic + Method Blueprint, 70% Pass, 12-Week Plan (Practice Questions)ArticleASNT NDT Level II Exam Guide 2026: Pick the Right Method and Pass10 min readArticleFREE ASNT NDT Level III Exam Guide 2026: Basic + Method Blueprint, 70% Pass, 12-Week Plan (Practice Questions)28 min read
2026 Statistics

Key Facts: ASNT NDT III RT Exam

135 MC

Exam Questions

ASNT RT method exam

4 hours

Time Limit

ASNT

70%

Typical Passing Score

ASNT psychometrics guidance

5 rem

Annual Whole-Body TEDE Limit

10 CFR 20.1201

75 days

Ir-192 Half-Life

Industrial radiography reference

0.020 in

Ug Limit Under 2 in Thick

ASME Section V Article 2 T-274.2

The ASNT NDT Level III RT method exam is a 135-question, 4-hour Pearson VUE test that confirms Level III authority for a radiographic-testing program. Tiered ASNT pricing applies and the passing score is typically reported around 70%. Content spans X-ray and gamma physics, equipment, geometric unsharpness, IQI/penetrameter selection, film and digital RT, 10 CFR 20 radiation safety, and code acceptance criteria from ASME Section V Article 2, AWS D1.1, and API 1104.

Sample ASNT NDT III RT Practice Questions

Try these sample questions to test your ASNT NDT III RT exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1X-rays are produced when high-energy electrons strike a target inside the X-ray tube. What primarily determines the maximum energy of the resulting X-ray spectrum?
A.The filament current (mA)
B.The peak accelerating voltage (kVp)
C.The cooling rate of the anode
D.The thickness of the tube window
Explanation: Maximum photon energy in the bremsstrahlung continuum equals the peak accelerating voltage applied between cathode and anode. Tube current (mA) controls beam intensity (number of photons per unit time), not maximum energy.
2Iridium-192 has a half-life of approximately 75 days. A new source assayed at 80 Ci will decay to roughly what activity after 150 days?
A.40 Ci
B.20 Ci
C.10 Ci
D.5 Ci
Explanation: Two half-lives have elapsed (150 / 75 = 2). Activity halves with each half-life: 80 -> 40 -> 20 Ci. Use A(t) = A0 * (1/2)^(t/T) for non-integer multiples.
3Cobalt-60 emits two principal gamma rays. What are their approximate energies?
A.0.40 MeV and 0.60 MeV
B.0.66 MeV (single)
C.1.17 MeV and 1.33 MeV
D.2.20 MeV and 2.50 MeV
Explanation: Co-60 decays by beta emission to excited Ni-60, which then emits gammas at 1.17 MeV and 1.33 MeV (average ~1.25 MeV). The higher energy gives Co-60 greater penetrating power than Ir-192 (~0.4 MeV average).
4Selenium-75 is increasingly used in industrial radiography because it offers an intermediate option between Ir-192 and X-rays. Approximately what is its half-life?
A.30 days
B.75 days
C.120 days
D.5.27 years
Explanation: Se-75 has a half-life of approximately 120 days. Its lower average gamma energy (~215 keV) provides better contrast on thinner steel sections than Ir-192, making it useful for thin-wall pipe radiography.
5The linear attenuation coefficient (mu) of a material is related to its half-value layer (HVL) by which expression?
A.HVL = mu / 0.693
B.HVL = 0.693 / mu
C.HVL = mu * 0.693
D.HVL = 2 / mu
Explanation: Because I = I0 * e^(-mu*x), the thickness that reduces intensity by 50% satisfies e^(-mu*HVL) = 0.5, giving HVL = ln(2)/mu = 0.693/mu. A larger mu means a thinner HVL.
6If the source-to-film distance (SFD) is doubled, by what factor does the radiation intensity at the film change, assuming no scatter changes?
A.Half the original
B.One-quarter of the original
C.Twice the original
D.Unchanged
Explanation: The inverse square law states intensity falls as 1/d^2. Doubling distance reduces intensity to 1/4. Exposure time must increase by a factor of 4 to maintain the same film density.
7Compton scattering predominantly affects radiographic image quality in what way?
A.Improves contrast by adding edge enhancement
B.Degrades contrast by adding non-image-forming scatter to the film
C.Increases definition by sharpening defect boundaries
D.Has no effect because scattered photons miss the film
Explanation: Compton scatter creates photons traveling in directions other than the primary beam that still reach the film. This adds fog (uniform exposure) that reduces subject contrast. Lead intensifying screens and filters help mitigate scatter.
8An Ir-192 source measured 100 Ci 50 days ago. Using a 75-day half-life, the current activity is approximately:
A.33 Ci
B.50 Ci
C.63 Ci
D.75 Ci
Explanation: A(t) = 100 * (0.5)^(50/75) = 100 * (0.5)^0.667. (0.5)^0.667 = e^(0.667 * ln 0.5) = e^(-0.462) = 0.63. Activity is approximately 63 Ci.
9The photoelectric effect is most likely to dominate over Compton scattering when:
A.Photon energy is very high and atomic number is low
B.Photon energy is low and atomic number is high
C.Photon energy equals 1 MeV exactly
D.The material is a gas at standard pressure
Explanation: Photoelectric absorption probability varies roughly as Z^3-Z^5 and inversely with E^3. It dominates at low photon energies in high-Z materials (lead screens absorb scatter via photoelectric effect). Compton dominates at intermediate energies.
10Increasing the kVp on an X-ray tube while holding mA-s constant produces what effect on the radiograph?
A.Increases subject contrast and reduces density
B.Reduces subject contrast and increases density
C.Has no effect on density or contrast
D.Increases unsharpness only
Explanation: Higher kVp produces a more penetrating, less-differentiating beam. Density increases (more photons reach film) and subject contrast decreases (less differential absorption between thicknesses). This is the classic kVp-vs-contrast tradeoff.

About the ASNT NDT III RT Exam

The ASNT NDT Level III Radiographic Testing (RT) method exam validates that a candidate already certified at the Basic Level III can serve as the technical authority for an RT program. The 135-question, 4-hour exam covers radiation physics (X-ray production, Ir-192/Co-60/Se-75 decay), exposure devices and source projectors, geometric unsharpness, IQI selection per ASME Section V Article 2, film and digital (CR/DR) imaging chains, radiation safety under 10 CFR 20 and 10 CFR 34, and welding acceptance criteria from AWS D1.1 and API 1104. This 100-question practice bank mirrors the public ASNT RT topic outline.

Assessment

135 multiple-choice questions covering RT physics, equipment, image quality, digital RT, radiation safety, and codes/standards

Time Limit

4 hours

Passing Score

70%

Exam Fee

Tiered (depends on member/nonmember status; ASNT publishes current pricing on its examinations page) (ASNT Certification Services LLC / Pearson VUE)

ASNT NDT III RT Exam Content Outline

~20%

RT Physics

X-ray tube production, bremsstrahlung and characteristic radiation, gamma source decay (Ir-192 ~75 d, Co-60 ~5.27 y, Se-75 ~120 d), attenuation coefficient mu, half-value layer (HVL = 0.693/mu), inverse square law, and photon interactions (photoelectric, Compton, pair production).

~16%

Equipment

X-ray tubes (focal spot, line focus, panoramic), constant-potential generators, gamma source projectors with depleted uranium shielding, collimators, source guide tubes, source-to-film distance, lead intensifying screens, GM and ion-chamber survey meters.

~18%

Exposure and Image Quality

Geometric unsharpness (Ug = F*t/d), film density requirements (1.8-4.0 per ASME Section V Article 2), hole and wire IQIs per SE-1025 and ASTM E747, 2-2T sensitivity, contrast, definition, backscatter 'B' lead-letter checks.

~14%

Film vs Digital RT

Industrial film per ASTM E1742, computed radiography per ASTM E2033 (photostimulable imaging plates), direct digital arrays, dynamic range, gray-scale bit depth (16-bit = 65,536 levels), basic spatial resolution (SRb) per ASTM E2002, normalized SNRn per ASTM E2737.

~16%

Radiation Safety

Units (rem/Sv, rad/Gy, Ci/Bq), 10 CFR 20 occupational dose limits (5 rem TEDE/yr, 15 rem lens, 50 rem skin and extremities), ALARA, time-distance-shielding, TLD/OSL dosimetry, alarm ratemeters per 10 CFR 34, postings, DOT 49 CFR Type B(U) transport packages.

~16%

Codes and Standards

ASME Section V Article 2 (Ug limits 0.020-0.070 in by thickness, IQI placement, density rules, identification, records), ASTM E1742/E747/E2033, AWS D1.1 RT acceptance for nontubular and tubular connections, API 1104 acceptance evaluated over any 12-inch (300 mm) weld increment.

How to Pass the ASNT NDT III RT Exam

What You Need to Know

  • Passing score: 70%
  • Assessment: 135 multiple-choice questions covering RT physics, equipment, image quality, digital RT, radiation safety, and codes/standards
  • Time limit: 4 hours
  • Exam fee: Tiered (depends on member/nonmember status; ASNT publishes current pricing on its examinations page)

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

ASNT NDT III RT Study Tips from Top Performers

1Memorize the three workhorse industrial gamma sources: Ir-192 (~75 d, avg ~0.4 MeV), Co-60 (~5.27 y, avg ~1.25 MeV), and Se-75 (~120 d, ~215 keV).
2Practice Ug = F*t/d, inverse square (intensity drops 1/d^2), reciprocity (mA-s and Ci-min equivalence), and HVL = 0.693/mu until they are reflexive.
3Drill ASME Section V Article 2 numbers: density 1.8-4.0 (2.0-4.0 for gamma), Ug limits 0.020/0.030/0.040/0.070 in by thickness band, and 2-2T IQI sensitivity.
4Know the difference between hole-type IQIs (ASME SE-1025) and wire-type IQIs (ASTM E747), including source-side placement and the F-marker rule for film-side placement.
5Treat 10 CFR 20 as a memorization domain: 5 rem TEDE/yr, 15 rem lens, 50 rem skin/extremity, 0.5 rem declared pregnant worker (gestation), 100 mrem/hr at 30 cm defines a high radiation area.
6Recognize 10 CFR 34 industrial radiography specifics: 500 mrem/hr alarm ratemeter setpoint, survey-meter calibration every 6 months, and survey-before-and-after every exposure.
7For digital RT, learn SRb (duplex-wire per ASTM E2002) and SNRn (per ASTM E2737) - these have largely replaced film density as the qualification metric in ASME Section V's digital appendices.
8When answering AWS D1.1 and API 1104 acceptance questions, remember: D1.1 always rejects cracks/incomplete fusion/incomplete penetration, and API 1104 evaluates RT indications over any 12-inch (300 mm) weld increment.

Frequently Asked Questions

What is the ASNT NDT Level III RT method exam?

It is the radiographic-testing method exam in ASNT's Level III certification scheme. After passing the Basic Level III exam, a candidate sits a 135-question, 4-hour RT method exam at Pearson VUE that tests RT physics, equipment, image quality, digital RT, radiation safety, and codes. Passing both the Basic and the RT method exam earns ASNT NDT Level III RT certification.

How many questions are on the RT method exam and how long is it?

The ASNT RT method exam is 135 multiple-choice questions with a 4-hour time limit (RT is one of the longer 'four-hour' method exams in ASNT's list, along with AE, ET, LT, and UT). Some questions are unscored pretest items.

What passing score do I need for the RT method exam?

ASNT does not publish a fixed per-exam passing percentage. Public ASNT psychometrics guidance places method-exam cut scores typically in the 70 to 80 percent range. A reasonable preparation target is mastery at or above 80 percent on a varied practice mix.

What does the RT exam emphasize most heavily?

Public ASNT material and the updated 2026 RT topic outline emphasize RT physics (sources, attenuation, geometry), image quality (Ug, density, IQI selection), interpretation, radiation safety under 10 CFR 20 and 34, and code-based acceptance per ASME Section V Article 2, AWS D1.1, and API 1104.

Do I need RT field experience before the method exam?

Yes. ASNT's Level III application requires documented experience in the method being certified, scaled by education level. The RT method exam asks scenario questions about procedure approval, geometry tradeoffs, and safety decisions that are difficult to answer without real shooting experience.

How much does the RT method exam cost?

ASNT prices its method exams in tiers (4-hour method tier applies to RT), with separate fees for ASNT members and nonmembers, plus an application fee that you pay once for the Level III application. Check the ASNT Examinations page for the current 2026 fee schedule.

Is the RT method exam open book?

No. The ASNT NDT Level III RT method exam is administered under standard closed-book ASNT method-exam rules at Pearson VUE or an ASNT Authorized Exam Center. Reference values such as common HVLs, code Ug limits, and dose limits must be memorized.