UGC NTA NET/JRF Exam, Forensic Science, August-2024

The correct sequence of firing and bolt operation in a firearm is:

A. When the bolt is drawn backward, the fired cartridge case is extracted from the chamber and trails along with the bolt - this is the beginning of the extraction process after firing.

D. When the bolt reaches a position where the cartridge comes in line with the ejection port, it strikes the ejector with a force and ejected out - the used cartridge is forcefully ejected.

B. In its backward journey, the gun is cocked also - the firing mechanism is reset (cocked) during this backward motion.

C. When the bolt is pushed forward, it piles the cartridge from the magazine and chamber ita new cartridge is pushed into the chamber.

E. The forward motion of the bolt locks the gun, seals the chamber by turning the bolt knob to one side - the chamber is sealed and ready for the next shot.

The correct sequence for analytical procedures in paint source identification is:

A. Microscopic Examination - initial examination for number of layers, colour distribution, and texture.

E. FTIR Analysis - Fourier Transform Infrared Spectroscopy is used to identify chemical composition of each layer.

C. Primer Colour Coding - identifying the primer layer using manufacturer standards.

D. Paint database query - matching findings with existing automotive paint databases like PDQ (Paint Data Query).

В. Торсоat Colour Coding - final step to correlate surface colour with vehicle model and make for source identification.

The traditional definition of death refers to irreversible and permanent cessation of vital functions, specifically:

A. Brain function - cessation indicates brain death, an accepted legal and medical indicator of death.

B. Respiratory activity - the permanent stopping of breathing.

C. Cardiac function - irreversible stoppage of heartbeat.
These three are the core life-support systems; their cessation confirms death. Functions like digestive or reproductive activity are non-essential for defining death.

In photographic developer solutions, preservatives serve critical roles, including:

B. To prevent wasteful oxidation of the developing agent - preservatives like sodium sulfite minimize unwanted oxidation.

C. To prevent the discoloration of the used developing solution with consequent risk of staining of negatives and prints - discoloration can lead to image artifacts.

E. To act as a silver halide solvent in certain fine-grain developer formula -in such formulations, preservatives help improve image resolution and grain quality.

Other listed roles like maintaining pH or activating developers are not the function of preservatives but of buffers and accelerators.

A. Ray search method is also known as the wheel search method, where investigators move outwards from a central point like spokes of a wheel, ideal for small, well-defined areas.

C. Quadrant search method is also referred to as the zone search method, where the crime scene is divided into zones or grids, and each section is searched individually - useful in large, complex scenes.

These are standard systematic search techniques used in crime scene investigation to ensure no evidence is missed.

'DIBs' (Drive Image Backup) and 'On Track' are Forensic Computer Investigation tools used by forensic experts for data recovery and analysis. Alongside these, tools like Forensic-X are designed for advanced forensic analysis, including digital image acquisition and examination.

B. Forensic-X enables structured evidence collection, indexing, and pattern detection.
C. Snap Back Dot Arrest is a data protection and system restoration mechanism that can be utilized during forensic imaging to preserve data integrity.

These tools collectively help in the investigation of cybercrime, digital fraud, and evidence recovery.

Regarding natural variation in handwriting, the following are correct:

D. The value of nature and extent of the variation around the master pattern will become evident in two handwriting having similar master pattern - This helps forensic document examiners distinguish between different individuals even with superficially similar writing.

A. A widely divergent master pattern can properly be considered to be a 'personal characteristic of the handwriting'- This refers to the fact that each writer has their own unique but variable range of writing, which forms their identifiable master pattern.

Natural variation is not a flaw, but rather a feature used in authorship verification, and must be studied across multiple samples.

B. Krumbein roundness chart is used to study the shape and roundness of sandy particles. It compares particle silhouettes to categorize grains based on angularity and sphericity, critical for soil forensics and sedimentology.

E. Power comparison chart may also be used in comparative studies of shape, form, or angularity, though it is less commonly referenced.
The Munsell soil colour chart (Option A) is used for color identification, not shape.

Barbiturates are classified by duration of action into long-acting, intermediate, short, and ultra-short.

(C) Phenobarbital and (E) Mephobarbital are classified as long-acting barbiturates, with effects lasting 6-12 hours or more.

They are commonly used in treating seizures or chronic epilepsy.
Other options like Amobarbital, Secobarbital, and Pentobarbital are short or intermediate-acting.

A. The position, size, and general shape of the firing pin and breech face marks on a cartridge are class characteristics - These are common to all firearms of a specific make or model, used to narrow down the firearm type.

B. Firearms of different makes and of different models of same make imprint different class characteristics - Because manufacturing specifications vary, even slight changes in design result in different class features.

In contrast, individual characteristics (not class) are formed by random imperfections such as striations on bullets, not the caliber or groove direction.