UGC NTA NET/JRF Exam, Forensic Science, December-2023

Total Questions: 100

81. In sexual assault case, the investigation proceeds in the following sequence:

(a) Examination of the victim by doctor
(b) Examination of clothing of the victim
(c) The psychological counselling of the victim
(d) The evidence packaged in tamper-evident packaging
Choose the correct answer from the options given below:

Correct Answer: B. (a), (d), (b), (c)
Solution:

In sexual assault cases, the investigation typically proceeds in the following sequence:

  • Examination of the victim by a doctor, which is crucial for documenting injuries and collecting forensic evidence such as swabs for DNA analysis.
  • The evidence is then packaged in tamperevident packaging to maintain the chain of custody and prevent contamination or loss.
  • Examination of the clothing of the victim follows, where forensic experts look for biological evidence such as semen, blood, or saliva.
  • The psychological counseling of the victim is also essential, although it often occurs concurrently with the investigation steps to support the victim's emotional and mental health.

Hence, the correct sequence is (a), (d), (b), (c).

82. Arrange the following in sequence within the firing range:

(a) Electrical detonator
(b) Main charge
(c) Electric current
(d) Booster
Choose the correct answer from the options given below: 

Correct Answer: A. (c), (a), (d), (b)
Solution:

Within the firing range, the sequence is as follows:

  • Electric current initiates the process by providing the necessary energy.
  • Electrical detonator then triggers the explosion.
  • Booster amplifies the explosion to ensure the main charge detonates effectively.
  • Main charge is the primary explosive that completes the sequence.

This order ensures a controlled and effective detonation process.
Hence, the correct sequence is (c), (a), (d), (b)

83. Arrange the proper sequence for the analysis of samples in GC:

(a) Vaporization takes place
(b) Samples, both liquid and gas are then introduced into the flowing gas stream
(c) The sample is injected by a hypodermic syringe through a self-sealing silicon rubber septum
(d) Samples are swept onto the column
Choose the correct answer from the options given below:

Correct Answer: B. (c), (a), (d), (b)
Solution:

The proper sequence for the analysis of samples in gas chromatography (GC) is:

The sample is injected by a hypodermic syringe through a self-sealing silicon rubber septum.

  • Vaporization takes place as the sample enters the heated injection port.
  • Samples are swept onto the column by the carrier gas.
  • Samples, both liquid and gas, are then introduced into the flowing gas stream.

This sequence ensures that the sample is properly introduced, vaporized, and carried through the GC system for analysis.
Hence, the correct sequence is (c), (a), (d), (b).

84. Arrange in proper sequence the steps followed for isolation of DNA from bones:

(a) Drilling
(b) Cleaning of the bone
(c) Lysis
(d) Decalcification
(e) Precipitation
Choose the correct answer from the options given below:

Correct Answer: C. (b), (a), (d), (c), (e)
Solution:

The proper sequence for isolating DNA from bones is:

  • Cleaning of the bone to remove any surface contaminants.
  • Drilling to obtain a bone powder sample.
  • Decalcification to remove the mineral content of the bone and make it easier to access the DNA. Lysis to break open the cells and release the DNA.
  • Precipitation to purify the DNA from the lysate.

This order ensures the bone is properly prepared and processed to extract highquality DNA.
Hence, the correct sequence is (b), (a), (d), (c), (e).

85. The correct order of analysis of petrol using T.L.C. method:

(a) Activation of T.L.C. plate
(b) Development & separation of petrol spot inside T.L.C. chamber
(c) Application of Petrol spot to the T.L.C. plate
(d) Visualization of developed T.L.C. plate by using spraying reagent
(e) Calculation of Rf value
Choose the correct answer from the options given below:

Correct Answer: B. (a), (c), (b), (d), (e)
Solution:

The correct order of analysis of petrol using the Thin Layer Chromatography (TLC) method is:

  • Activation of the TLC plate to ensure it is ready for use.
  • Application of the petrol spot to the TLC plate.
  • Development and separation of the petrol spot inside the TLC chamber, where the components of the petrol are separated based on their affinities to the stationary phase.
  • Visualization of the developed TLC plate by using a spraying reagent to make the spots visible.
  • Calculation of Rf value, which is the ratio of the distance traveled by the compound to the distance traveled by the solvent front, providing a quantitative measure of the components.

This sequence ensures accurate and reliable separation and analysis of petrol components.

86. Given below are two statements:

Statement I: Pyrolysis gas chromatography is the most suitable techniques used to distinguish most paint binder formulation.

Statement II: Infrared spectroscopy can also be used to distinguish paint binder formulations.

In the light of the above statements, choose the correct answer from the options given below:

Correct Answer: A. Both Statement I and Statement II are true
Solution:

Pyrolysis gas chromatography is indeed a suitable technique used to distinguish most paint binder formulations due to its ability to break down complex polymers into simpler compounds that can be separated and analyzed.

Infrared spectroscopy can also distinguish paint binder formulations by identifying the specific functional groups and molecular structures within the binders. Both techniques are effective in forensic paint analysis.

87. Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): All three dimensional footwear impressions should be casted with dental stone.

Reason (R): Dental stone sets are much harder and have higher compressive strength, retain greater detail.

In the light of the statements, choose the correct answer from the options given below:

Correct Answer: A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
Solution:

Three-dimensional footwear impressions should be cast with dental stone because dental stone sets much harder and has higher compressive strength compared to other casting materials.

This results in casts that retain greater detail, making dental stone the preferred choice for capturing detailed impressions of footwear marks.

88. Given below are two statements:

Statement I: The arrangement of the writing on the paper may be as individual as the writing itself.

Statement II: Margin, spacing, crowding, insertions and alignment are personal habits.

In the light of the above statements, choose the correct answer from the options given below:

Correct Answer: A. Both Statement I and Statement II are true
Solution:

The arrangement of writing on the paper, including margins, spacing, crowding, insertions, and alignment, can be as individual as the handwriting itself.

These aspects are personal habits that can vary significantly between individuals, contributing to the uniqueness of a person's writing style.

89. Given below are two statements:

Statement I: One of the types of brain death is cortical or cerebral death where there is intact brain stem.

Statement II: It produces a vegetative state in which respiration continues, but there is total loss of power of perception by the senses.

In the light of the above statements, choose the most appropriate answer from the options given below:

Correct Answer: A. Both Statement I and Statement II are correct
Solution:

Cortical or cerebral death is a type of brain death where there is intact brain stem function, resulting in a vegetative state.

In this condition, respiration continues due to the intact brain stem, but there is a total loss of power of perception by the senses, leading to a lack of awareness and cognitive function.

90. Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): Leuco crystal violet, Amino black, Diamino benzidine (DAB), Luminol and Fuchsin acid reagents used to enhance Impressions.

Reason (R): These methods can enhance only non-bloody footwear Impressions.

In the light of the statements, choose the correct answer from the options given below:

Correct Answer: C. (A) is correct, but (R) is not correct
Solution:

Leuco crystal violet, amino black, diamino benzidine (DAB), luminol, and fuchsin acid are reagents used to enhance impressions, including bloody footwear impressions.

These reagents react with components in blood or other substances to make the impressions more visible.

Therefore, the assertion (A) is correct, but the reason (R) is incorrect because these methods can enhance both bloody and nonbloody impressions.