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

Total Questions: 100

91. (Qs. No. 91-95): Read the following passage carefully and answer the questions that follow:

A female reported the Sub-Divisional Magistrate of her locality, that her husband had attempted to murder her by strangulation. On examination, bruise like marks were noticed on both sides of the front of the neck.

The skin around these marks was inflamed and covered with tiny blisters. Similar marks were noticed on her palms and tips of the fingers. On further examination, these marks were found to have been caused by the application of the juice of marking nut.

Taken in larger doses, Marking Nut produces:
(a) Blisters on the throat
(b) Convulsion
(c) Gastro-intestinal irritation
(d) Sedation
Choose the most appropriate answer from the options given below: 

Correct Answer: C. (a) and (c) only
Solution:

The marking nut is well-known for causing blisters on the skin and intense gastrointestinal irritation when ingested in larger doses. This is due to its high concentration of caustic and allergenic substances, especially anacardic acids.

It's a potent irritant, and can lead to severe abdominal pain, vomiting, diarrhea, and systemic toxicity, which can lead to unconsciousness, convulsion, and even death in severe cases.

Thus, in larger doses, it produces not only blisters on the skin but also severe gastrointestinal irritation.

92. Marking Nut belongs to which of these category:

Correct Answer: B. Irritant
Solution:

The marking nut belongs to the category of Irritants. It is a strong vesicant (blistercausing agent) and a gastrointestinal irritant when ingested. This is because it contains anacardic acid, bhilawanol, and semecarpol, which are all highly irritating compounds.

These substances can cause blistering and severe inflammation of the skin and mucous membranes. In addition, these compounds can cause serious damage to the digestive system when ingested.

93. Who is authorized to register her complaint (FIR)?

Correct Answer: B. Police
Solution:

In India, the police are the authority to register a First Information Report (FIR) in cases of a cognizable offense, such as attempted murder.

The Sub-Divisional Magistrate (SDM) may have a supervisory role in ensuring law and order in their jurisdiction, but the direct registration of the FIR, initiation of the investigation, and further law enforcement procedures fall under the purview of the police.

94. The juice of marking nut causes death if applied to:

Correct Answer: C. Scrotum

95. Marking Nut could have been procured from:

Correct Answer: B. Laundry

96. (Qs. No. 96-100): Read the following passage carefully and answer the questions that follow:

A chromatographer was given a mixture containing 4 analytes namely W, X, Y, Z to be separated using High Performance Liquid Chromatography (HPLC).

The HPLC was an isocratic system, a C-18 column (C-18. 250 mm × 5 mm) and has UV detector. The chromatographic data obtained is given as under:

AnalyteRetention Time (min)Width of Peak at base (mm)
Non Retained3.1—
W5.40.41
X13.31.07
Y14.11.16
Z21.61.72

From the obtained chromatographic data, calculate the retention factor for the analyte 'W'? 

Correct Answer: B. 0.74

97. What is the difference between the retention factor of analyte X and analyte Y?

Correct Answer: B. 0.2
Solution:

To determine the difference in retention factor between X and Y, we first need to calculate their respective retention factors using the formula stated in Q 96.

The retention factor for X is (13.3 – 3.1) / 3.1 = 3.29 and for Y, it's (14.1 - 3.1) / 3.1 = 3.55. The difference between these two values is 3.55 - 3.29 = 0.26, which is closest to 0.2, hence option B is correct.

98. As a chromatographer, to decrease the retention time of analyte Z without altering the retention time of other compounds what modification in the developed method should be proposed.

Correct Answer: B. Increasing of flow rate after elution of analyte Y
Solution:

In order to decrease the retention time of analyte Z without altering the retention time of other compounds, one of the possible modifications could be to increase the flow rate after the elution of analyte Y.

This is because increasing the flow rate would push the analytes through the column faster, reducing the retention time for those analytes eluted after the flow rate change.

Thus, if the flow rate is increased after Y has eluted, Z's retention time will decrease while the retention times of W, X, and Y remain unaffected. This is option B.

99. Looking at the chromatographic data, which range describe correctly the resolution of X and Y.

Correct Answer: B. Some where between 90% to 70%
Solution:

The resolution in chromatography describes the degree of separation between two peaks. In this case, the retention times of X and Y are very close together, suggesting the peaks might overlap to some extent.

However, without having specific resolution calculations, one can't precisely determine the resolution percentage. Given that their retention times and peak widths are relatively close, it is likely that their resolution falls somewhere between 70% and 90%, hence option B.

100. From the obtained chromatographic data which one of the following correctly describe the analyte Z in comparism to analyte W.

Correct Answer: A. Non-polar in nature
Solution:

The analyte Z has the highest retention time in the chromatographic data, meaning it interacts most strongly with the stationary phase. In the context of a C-18 column, which is non-polar, this implies that Z is more nonpolar than W.

The more non-polar an analyte is, the longer it will be retained on a nonpolar stationary phase due to the increased interactions. Therefore, we can say that Z is more non-polar than W, which makes option A the correct answer.