UGC NTA NET/JRF Exam, Forensic Science, June-2025

Total Questions: 100

61. Which of these is used as a chemical enhancement reagent for detecting blood stains?

Correct Answer: 2. Leuco crystal violet reagent
Solution:

Leuco Crystal Violet (LCV) is widely used in forensic science as a chemical enhancement reagent for visualizing bloodstains.

It is initially colorless but, in the presence of hemoglobin and hydrogen peroxide, gets oxidized to crystal violet-a bright purple dye.

This reaction highlights latent or faint bloodstains, even on surfaces where blood might have been cleaned or diluted, making it a valuable presumptive test in crime scene investigations.

62. Name the test where a mould is filled with cement paste, submerged in water and boiled to measure the expansion:

Correct Answer: 1. Le Chatelier test
Solution:

The Le Chatelier test determines the soundness of cement, i.e., its ability to retain volume stability after setting. A mould filled with cement paste is submerged in water and then boiled.

Expansion is measured to detect unsoundness caused by free lime or magnesia. Although autoclave methods also test soundness, the description given (boiling water bath method) specifically matches the Le Chatelier test.

63. The _______ of the lens is a set of blades that forms the variable lens openings.

Correct Answer: 1. Diaphragm
Solution:

The diaphragm in a lens is a system of overlapping blades that form a variable opening. This regulates how much light enters the camera. The opening itself is called the aperture, which is measured in f-stops.

The diaphragm works much like the iris of the eye-expanding or contracting to control light. Aberrations are lens defects, while exposure meters measure light levels but are not part of the lens itself.

64. What are "immobilines" in the context of isoelectric focusing?

Correct Answer: 3. Modified acrylamide monomers with acidic or basic properties
Solution:

In isoelectric focusing, immobilines are modified acrylamide monomers carrying acidic or basic functional groups. When incorporated into the gel, they establish a fixed pH gradient.

This eliminates drift associated with carrier ampholytes and allows proteins to migrate until they reach their isoelectric point (pI). Because immobilines "immobilize" the pH, they provide reproducibility and sharper separation in protein analysis.

65. A percussion cap having 'V' shaped anvil, is known as:

Correct Answer: 1. Boxer
Solution:

The Boxer primer contains a self-contained V-shaped anvil inside the primer cup. When struck by the firing pin, the priming compound is crushed between the cup and the anvil, igniting the propellant.

Boxer primers are easy to reload because the cartridge has a single central flash hole.

By contrast, Berdan primers have two flash holes and the anvil built into the cartridge case, making reloading more difficult.

66. Match List-I with List-II:

List-IList-II
A. The firearms made by blacksmith by not adhering to any specification.I. Derringers
B. In the priming mixture, potassium chlorate acts asII. Graphite
C. Small-pocket firearms having multiple barrels, each of which is loaded and fired separately.III. Oxidizer
D. Material used for coating propellant grains to eliminate static electricity.IV. Zip-guns

Choose the correct answer from the options given below:

Correct Answer: 4. A-IV, B-III, C-I, D-II
Solution:

A. Zip-guns (IV): Crude firearms manufactured by local blacksmiths without standard specifications.

B. Potassium chlorate (III): Acts as an oxidizer in priming mixtures, supplying oxygen for ignition.

C. Derringers (1): Small pocket firearms with multiple barrels, each loaded and fired separately.

D. Graphite (II): Used to coat propellant grains, reducing static electricity and improving flow.

67. Arrange the following in chronological order regarding the establishment of CFSL's in India.

A. Pune
B. Delhi
C. Calcutta (Kolkata)
D. Hyderabad
Choose the correct answer from the options given below:

Correct Answer: 3. C, D, B, A
Solution:

The chronological order of CFSL establishments in India is:
• Calcutta (Kolkata) - the first CFSL, established in 1957.
• Hyderabad - the second, in 1967.
• Delhi - set up later in 1968.
• Pune - established much later in 1977

68. Insects can be used to determine many factors about a death scene, except:

Correct Answer: 2. The nature of poison consumed cannot be determined
Solution:

Forensic entomology uses insect evidence to estimate the time since death, determine if the body was moved, and sometimes indicate wound location based on insect colonization patterns.

However, while some toxins may affect insect development, insect evidence generally cannot reliably identify the specific poison consumed by the deceased.

69. The ballistic co-efficient of the projectile (C) is given by:

Correct Answer: 2.
Solution:

The ballistic coefficient (C) measures how well a projectile overcomes air resistance. It is expressed as: C = W/nd²

Where W is the weight of the projectile, d its cross-sectional diameter, and n a coefficient of form or reduction. This formula balances mass and drag surface area, making it fundamental in external ballistics.

70. The fingerprint pattern of a person is as follows: Whorl pattern on right middle, right little, left index, left middle fingers; arch pattern present on right ring and left thumb and rest all the fingers have loop pattern. Based on the above pattern, what will be the primary classification?

Correct Answer: 4. 3/15
Solution:

In Henry's Primary Classification, values are assigned to whorl patterns in a specific finger order. Whorls are present on:
• Right middle (value 2)
• Right little (value 16)
• Left index (value 8)
• Left middle (value 4)
Total for even fingers = 16 + 4 = 20 → add 1 = 21
Total for odd → add 1 = 11 fingers = 2 + 8 = 10
Thus, the fraction reduces to 5/13 when normalized in the system's ratio form.