Mock Test Set- 16 (Forensic Science)

Mock Test Set- 16

Q1. Which statistical model is most suitable for evaluating trace evidence such as soil or fiber comparisons?

A) Bayesian Network

B) Principal Component Analysis

C) Student's t-test

D) Linear Regression

Answer: A) Bayesian Network

Explanation: Bayesian Networks provide probabilistic frameworks to evaluate the likelihood ratio in forensic evidence, especially for trace evidence like soil or fibers where variability is high.

Q2. In fire debris analysis, what is the primary role of Activated Charcoal Strips (ACS)?

A) Absorption of metal ions

B) Selective adsorption of ignitable liquids

C) Colorimetric detection of hydrocarbons

D) Removal of moisture content

Answer: B) Selective adsorption of ignitable liquids

Explanation: ACS is widely used for passive headspace extraction to selectively adsorb ignitable liquid vapors from fire debris without affecting other volatile organic compounds.

Q3. Which of the following is a direct indicator of TNT in post-blast residue by Gas Chromatography-Mass Spectrometry (GC-MS)?

A) m/z 228

B) m/z 210

C) m/z 246

D) m/z 181

Answer: D) m/z 181

Explanation: The ion at m/z 181 is a characteristic fragment of TNT detected during GC-MS analysis due to its nitroaromatic structure.

Q4. What is the primary difference between RDX and PETN in FTIR spectroscopy?

A) Nitro group absorption peaks

B) Symmetric stretching of C=O

C) Asymmetric stretching of N-O

D) Amine group absorption

Answer: A) Nitro group absorption peaks

Explanation: RDX exhibits sharp peaks around 1570 cm⁻¹ and 1300 cm⁻¹ corresponding to asymmetric and symmetric NO₂ stretching, while PETN shows additional peaks due to nitrate ester groups.

Q5. Which technique is used to differentiate isomers of methamphetamine in seized drug samples?

A) UV-Vis Spectroscopy

B) Chiral Gas Chromatography

C) Raman Spectroscopy

D) Atomic Absorption Spectroscopy

Answer: B) Chiral Gas Chromatography

Explanation: Chiral GC separates enantiomers of methamphetamine (D- and L-isomers) based on their interactions with chiral stationary phases, which is crucial in forensic toxicology.

Q6. Which method provides the most conclusive identification of inorganic explosive residues?

A) SEM-EDS

B) Raman Spectroscopy

C) GC-MS

D) UV-Vis Spectroscopy

Answer: A) SEM-EDS

Explanation: Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) identifies elemental composition and morphology of inorganic explosive residues like ammonium nitrate and potassium nitrate.

Q7. What is the forensic significance of the oxygen balance in explosives?

A) Indicates chemical purity

B) Determines the heat of combustion

C) Predicts the amount of unreacted residue

D) Correlates with the velocity of detonation

Answer: D) Correlates with the velocity of detonation

Explanation: Oxygen balance affects the explosive's ability to produce gaseous products and influences detonation velocity, where zero balance indicates complete combustion.

Q8. In forensic glass analysis, Laser Ablation-Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) is used to measure:

A) Refractive Index

B) Isotopic Ratios of Trace Elements

C) Density

D) Thickness

Answer: B) Isotopic Ratios of Trace Elements

Explanation: LA-ICP-MS is highly sensitive and used to determine trace elemental composition and isotopic ratios, providing high discrimination in forensic glass analysis.

Q9. The hydrolysis of PETN in forensic samples produces:

A) Nitroglycerin

B) Pentaerythritol

C) Glycerol Trinitrate

D) Ammonium Nitrate

Answer: B) Pentaerythritol

Explanation: Hydrolysis of PETN in aqueous solutions breaks down into pentaerythritol and nitric acid, aiding in the identification of the explosive.

Q10. What is the primary chemical component detected in latent fingermarks using Physical Developer (PD)?

A) Amino acids

B) Lipids

C) Metal ions

D) Sugars

Answer: B) Lipids

Explanation: Physical Developer detects latent prints by depositing silver on lipid residues left by sebaceous secretions, making it highly effective on wet or porous surfaces.

Content Writer:- Srishti Dutta