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

In the permanent dentition, there are 32 teeth, with 16 teeth in each jaw (maxillary and mandibular). These are symmetrically arranged on each side of the jaw as follows:
4 incisors (2 central and 2 lateral)
2 canines (1 on each side)
4 premolars (2 on each side)
6 molars (3 on each side)
This results in the dental formula for adults:
(2 Incisors + 1 Canine + 2 Premolars + 3 Molars) × 4 = 32 teeth
This arrangement allows for effective biting, tearing and grinding of food.

A rebated cartridge case is a type where the extractor flange (rim) is smaller in diameter than the body of the cartridge case. Additionally, it features a groove around the body in front of the flange, which helps in extraction.

This design is used to allow compatibility with specific bolt faces while utilizing a wider cartridge body for increased powder capacity or ballistic performance.

Rebated rims are common in some magnum and automatic firearm cartridges due to their unique balance of chambering efficiency and extraction mechanics.

Acetaminophen (also known asa paracetamol) is classified as a mild analgesic and antipyretic. It is widely used for relieving pain and reducing fever, but it has little to no anti-inflammatory effect, unlike NSAIDs.

It is considered safer than opioid analgesics like codeine, tramadol, or oxycodone, especially for mild to moderate pain. However, excessive doses can lead to liver toxicity.

Due to its non-narcotic nature, acetaminophen is not addictive and is included in over-the-counter medications.

Alan Boyde developed a method of age estimation using incremental lines, particularly in tooth enamel and dentin.

These incremental lines of Retzius in enamel and Andresen lines in dentin reflect daily and periodic mineral deposition, and their count and spacing can be used to estimate the age of an individual with high accuracy.

This method is especially useful in forensic odontology, anthropology, and archaeological studies for age profiling from human remains, particularly in subadults.

Greenhill's formula is a classical equation used to calculate the optimal rifling twist rate in a firearm barrel for stabilizing a bullet. The formula is:
Twist (in calibers) = 100/Length of bullet (in calibers)

This formula assumes standard bullet shape and density and helps in maintaining gyroscopic stability of the bullet in fight.

It is most applicabile for long cylindrical bullets and was originally developed in the 19th century for use in artillery but adapted to small arms later.

In the life cycle of an insect, the pupa stage is referred to as the resting and inactive stage. During this stage, the insect is usually immobile and enclosed within a protective casing (e.g., chrysalis or cocoon).

Despite its outward inactivity, intensive internal transformation occurs, where the larval structures are broken down and reorganized into adult structures - a process known as metamorphosis.

This stage is characteristic of holometabolous insects (complete metamorphosis), such as butterflies, beetles, and flies.

The retardation (R) or air resistance encountered by a standard projectile in ballistics is expressed by the equation R = AVⁿ, where: A is a constant that depends on shape, mass, and air density,
V is the projectile's velocity,
n is an empirically determined constant, typically between 1 and 2 depending on speed (e.g., near 2 at supersonic speeds). This formula helps in calculating projectile deceleration due to air drag, which is crucial in forensic and external ballistics for trajectory reconstruction.

The correct sequence for introduction of watermarks into paper during the papermaking process is:
C. The paper pulp travelling on the endless wire belt this is the beginning of sheet formation.

D. The water is draining away through mesh - as the slurry moves, water drains through the wire mesh, leaving cellulose fibers behind.

A. Cellulose fibres are retained and felted through its vibratory motion - the mesh vibrates to help fibers interlock and form a mat.

E. The moist web of fibres then passes under the 'dandy roll' - this roller carries the watermark design.

B. Raised letters and designs on the dandy roll, presses onto the moist web to compress and thin out the fibres - this creates the watermark by varying paper thickness.