Forensic Chemistry: Brisance, VoD, Oxygen Balance and Sensitivity
Published:
Questions
28
Duration
30 min
Faculty-reviewed
0
Updated
24 May 2026
About this mock
UGC-NET Forensic Science Unit VI advanced drill on the physical and thermochemical characterisation of secondary high explosives. Hard-band questions cover detonation velocity (VoD in m/s: HMX 9100, RDX 8750, PETN 8350, TNT 6900, ANFO 3200), brisance measurement by the Trauzl lead-block compression test and the Kast brass cylinder compression test (both derived from the Chapman-Jouguet pressure approximation rho x VoD^2), oxygen balance stoichiometry (OB%% formula, TNT at -74%%, RDX at -21.6%%, PETN at -10.1%%, ANFO near zero), and sensitivity testing by drop-weight impact (J), BAM friction (N), DTA/DSC thermal onset (degrees C), and electrostatic spark (mJ).
Chapman-Jouguet detonation pressure calculations and the Hopkinson-Cranz scaled distance law are tested alongside power index and TNT equivalence values (RDX 1.60x, PETN 1.66x, ANFO 0.74x). Indian regulatory coverage spans UN Class 1 divisions (1.1 mass explosion hazard through 1.6 extremely insensitive) and PESO licensing tiers under the Explosives Act 1884 and Explosives Rules 2008 (Form LE-1 for manufacture, LE-3 for storage, LE-4 for import, LE-7 for road transport). Each question tests one specific numerical or definitional parameter -- distractors differ on a single value, forcing genuine recall rather than elimination.
Topics covered:
- Detonation velocity: HMX, RDX, PETN, TNT, ANFO ranked values in m/s
- Brisance: Trauzl lead-block volume (cm3) and Kast brass cylinder height reduction (mm)
- Oxygen balance: OB%% formula derivation and calculated values for four explosives
- Sensitivity: drop-weight (J), BAM friction (N), DTA onset (degrees C), spark (mJ)
- Chapman-Jouguet pressure: rho x VoD^2 / 4 calculation and ranking
- Power index: RDX, PETN, ANFO values relative to TNT = 1.00
- Indian classification: UN Divisions 1.1 to 1.6 and PESO LE-licence categories
Calibrated for UGC-NET Paper II Unit VI top-decile candidates and NFSU MSc Forensic Chemistry entrance examinees. Allow 30 minutes.
Sources & references
Questions in this mock are written and verified against the following sources. Citations are recorded per question and shown in the explanation after submission.
- cited in 10 questions
Cooper, P.W. & Kurowski, S.R. -- Introduction to the Technology of Explosives, Wiley-VCH
Chapter 4: Brisance and Detonation Pressure, Chapman-Jouguet approximation
- cited in 8 questions
Akhavan, Jacqueline -- The Chemistry of Explosives, 4th Edition, Royal Society of Chemistry
Chapter 2: Oxygen Balance, TNT worked calculation (C7H5N3O6 = OB -74%%)
- cited in 7 questions
Meyer, Kohler, Homburg -- Explosives, 7th Edition, Wiley-VCH
Section: TNT, Detonation Velocity, Density Dependence
- cited in 2 questions
United Nations -- Recommendations on the Transport of Dangerous Goods, Model Regulations (Orange Book)
Chapter 2.1: Classification of Explosives, Division 1.4 Minor Hazard Definition
- cited in 1 question
Explosives Act 1884 and Explosives Rules 2008, Government of India
Schedule II: Licence Forms -- Form LE-1 (Manufacture), LE-3 (Storage), LE-4 (Import), LE-7 (Transport)
Open source
How our mocks are built
Questions are written and edited by the ForensicSpot team and cited from peer-reviewed forensic textbooks, official syllabi and primary case law. Each one is verified before publishing. Detailed explanations show after you submit, so the test stays a real test. See a mistake? Tell us.
Common questions
What does the Forensic Chemistry: Brisance, VoD, Oxygen Balance and Sensitivity mock cover?+
UGC-NET Forensic Science Unit VI advanced drill on the physical and thermochemical characterisation of secondary high explosives. Hard-band questions cover detonation velocity (VoD in m/s: HMX 9100, RDX 8750, PETN 8350, TNT 6900, ANFO 3200), brisance measurement by the Trauzl lead-block compression test and the Kast brass cylinder compression test (both derived from the Chapman-Jouguet pressure approximation rho x VoD^2), oxygen balance stoichiometry (OB%% formula, TNT at -74%%, RDX at -21.6%%,
How many questions and how long is the test?+
28 multiple-choice questions, 30 minutes total. Difficulty: hard. Tier: Premium.
Who is this mock for?+
Forensic science students and aspirants who want timed, exam-style practice with explanations and verified source citations on Forensic Chemistry, NET. Useful for postgraduate entrance preparation and for BSc / MSc forensic students testing their recall under time.
Are the questions reviewed?+
Each question carries a verified source citation. Faculty review for individual questions is in progress.
Do I need an account to take this mock?+
Yes, a free ForensicSpot account is required to start a timed attempt — this lets you save progress, see per-question explanations after submission, and track your topic-level performance over time.