Mock Test Set- 10

Q1. In forensic applications involving fire debris analysis, which stationary phase in gas chromatography would be the most suitable for analyzing hydrocarbons and their byproducts?

A) Polyethylene glycol

B) Dimethylpolysiloxane

C) Cyanopropylphenyl

D) Carbowax

Answer: B) Dimethylpolysiloxane

Explanation: Dimethylpolysiloxane is a non-polar stationary phase, making it highly suitable for separating hydrocarbons, which are common in fire debris analysis.

Q2. Which is the most reliable method for determining time since death within the first 24 hours?

   a) Rigor mortis

   b) Livor mortis

   c) Body temperature (algor mortis)

   d) Vitreous potassium levels

   Answer: c) Body temperature (algor mortis)

   Explanation: Body temperature decreases predictably after death, making it a reliable method for estimating time since death within the first 24 hours.

Q3. Which of the following is NOT an advantage of using capillary columns over packed columns in forensic gas chromatography?

A) Higher resolution

B) Shorter analysis time

C) Greater sample loading capacity

D) Better separation of complex mixtures

Answer: C) Greater sample loading capacity

Explanation: Capillary columns offer higher resolution, faster analysis, and better separation of complex mixtures, but they have lower sample loading capacity compared to packed columns.

Q4. In forensic ballistics, a “rifling” mark is a:

   a) Impression on the cartridge case

   b) Striation on the bullet

   c) Scratch on the firing pin

   d) Fracture pattern on the bullet jacket

   Answer: b) Striation on the bullet

   Explanation: Rifling marks are striations left on a bullet as it passes through the barrel of a rifled firearm.

Q5. Which of the following methods is used to determine mitochondrial DNA in degraded samples?

   a) STR analysis

   b) PCR

   c) Y-STR typing

   d) SNP analysis

   Answer: b) PCR

   Explanation: PCR (Polymerase Chain Reaction) amplifies mitochondrial DNA, which is abundant and survives better in degraded samples.

Q6. Which of the following types of stationary phases is most suitable for separating chiral compounds in forensic gas chromatography?

A) Polyethylene glycol (PEG)

B) Cyclodextrin-based phases

C) Dimethylpolysiloxane

D) Silica-based phases

Answer: B) Cyclodextrin-based phases

Explanation: Cyclodextrin-based stationary phases are used to separate chiral compounds due to their ability to form inclusion complexes with different enantiomers, making them valuable in forensic toxicology.

Q7. Which of the following is a hallmark of a gunshot wound of entrance?

   a) Stellate tear

   b) Abrasion collar

   c) Scalloped edges

   d) Irregular margins

   Answer: b) Abrasion collar

   Explanation: An abrasion collar is characteristic of entrance wounds caused by the bullet's friction as it enters the body.

Q8. In forensic entomology, the first insect group to colonize a corpse is usually:

   a) Blowflies

   b) Beetles

   c) Ants

   d) Spiders

   Answer: a) Blowflies

   Explanation: Blowflies are typically the first to arrive at a corpse, attracted to decaying tissue, and are crucial for estimating postmortem intervals.

Q9. A forensic scientist is analyzing drug metabolites using Gas Chromatography. The scientist notices peak tailing in the chromatogram. Which of the following is the most likely cause of this issue?

A) High column temperature

B) Inert carrier gas

C) Improper sample injection technique

D) Excessive carrier gas flow rate

Answer: C) Improper sample injection technique

Explanation: Peak tailing often occurs due to improper sample injection or overloading of the sample. Ensuring correct injection techniques can reduce this issue.

Q10. Which type of glass fracture is most commonly seen at the point of impact in a shooting incident?

   a) Radial fracture

   b) Concentric fracture

   c) Cone fracture

   d) Tangential fracture

   Answer: c) Cone fracture

   Explanation: Cone fractures occur at the point of impact, especially in glass, and have a conical shape due to the force of the bullet.

Content Writer:- Srishti Dutta