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

Total Questions: 100

71. Match List-I with List-II:

List-I (Name of Drug)List-II (Shape of Crystal)
(a) Cocaine(i) Forked rods
(b) MDMA(ii) White X shaped
(c) Methamphetamine(iv) Long Yellow rods
(d) Amphetamine(iv) Long Yellow rods

Choose the correct answer from the options given below:

(a)(b)(c)(d)
A.(ii)(iii)(iv)(i)
B.(iii)(ii)(i)(iv)
C.(iii)(iv)(i)(ii)
D.(i)(ii)(iii)(iv)
Correct Answer: В.
Solution:

The crystal shape of a drug can vary widely and isn't typically used as a primary method of identification due to this variability and lack of distinctive characteristics.

However, in many cases, a microscope might be used to observe the crystalline structure of an unknown substance. The question doesn't provide a clear and accurate correlation between the listed drugs

72. Match List-I with List-II:

List-I (Additives)List-II (Action)
(a) Stabilizers(i) reduce the flame temperature
(b) Plasticizers(ii) increase shelf life of propellant
(c) Coolants(iii) reduce burning rate of grain surface
(d) Surface moderants(iv) gelation of nitrocellulose

Choose the correct answer from the options given below:

(a)(b)(c)(d)
A.(i)(ii)(iii)(iv)
B.(ii)(iv)(i)(iii)
C.(iii)(ii)(i)(iv)
D.(ii)(i)(iv)(iii)
Correct Answer: B.
Solution:

Additives are substances added to products to improve their properties. Stabilizers increase the shelf life of a propellant, thereby preventing it from decomposing prematurely. Plasticizers are added to materials to increase their plasticity or fluidity, but in the case of propellant, they gel nitrocellulose which is a main component in some types of propellant.

Coolants are substances that, in this context, reduce the flame temperature. Lastly, surface moderants reduce the burning rate of the grain surface, controlling the rate of gas production and therefore the power of the propellant.

73. Match List-I with List-II:

List-I (Computer Crime)List-II (Description)
(a) Intrusion(iv) It involves obtaining unauthorized access to a computer
(b) Compromise(i) Replacing or modifying part of a computer system to facilitate an authorized access
(c) Spamming(ii) Sending unsolicited messages, usually emails
(d) Back door(iii) A program which open access to a machine from the outside to allow an unauthorized intruder into the machine

Choose the correct answer from the options given below:

(a)(b)(c)(d)
A.(iv)(i)(ii)(iii)
B.(i)(iii)(iv)(ii)
C.(ii)(iii)(iv)(i)
D.(iii)(i)(ii)(iv)
Correct Answer: A.
Solution:

Intrusion (iv) refers to unauthorized access to a computer system. It involves gaining access to a system without the consent of the owner. Compromise (i) refers to replacing or modifying part of a computer system to facilitate unauthorized access.

Spamming (ii) involves sending unsolicited messages, typically emails, to multiple recipients. A backdoor (iii) is a program which opens access to a machine from the outside, allowing an unauthorized intruder into the machine.

74. Match List-I with List-II:

List-IList-II
(a) Single Shot Pistol(i) The revolvers in which on pressing the cylinder latch on the side of frame and pushing the cylinder to the left exposing the chambers is swing back after loading into the frame
(b) Swing-out revolver(ii) A pistol has one firing chamber integral with the barrel, loaded manually each time the weapon is to be fired.
(c) Derringers(iii) A rifle with shortened barrel.
(d) Carbine(iv) Small pocket firearms having multiple barrels, each of which is loaded and fired separately

Choose the correct answer from the options given below:

(a)(b)(c)(d)
A.(iii)(i)(iv)(ii)
B.(i)(iii)(ii)(iv)
C.(ii)(i)(iv)(iii)
D.(ii)(iii)(iv)(i)
Correct Answer: C.
Solution:

Single-shot pistols (ii) are firearms that are designed to fire a single round each time they are loaded. Swing-out revolvers (i) have a design in which the cylinder containing the rounds swings out to the side for loading and unloading.

Derringers (iv) are a type of small pocket firearm with multiple barrels that are each loaded and fired separately. Carbines (iii) are rifles with shortened barrels, making them lighter and easier to handle, especially in close quarters.

75. Match List-I with List-II:

List-IList-II
(a) Microprinting(i) Dandy roll
(b) Water marks(ii) Passport
(c) Hologram(iii) Difficult to read by naked eye
(d) Fluorescent fibres(iv) 3-D laser printed image

Choose the correct answer from the options given below:

(a)(b)(c)(d)
A.(i)(iii)(iv)(ii)
B.(iii)(i)(iv)(ii)
C.(ii)(iii)(i)(iv)
D.(iii)(iv)(ii)(i)
Correct Answer: B.
Solution:

Microprinting (iii) is a security feature commonly used in banknotes and other valuable documents. It involves printing text or patterns so small that they are difficult to read with the naked eye.

Watermarks (i), produced by dandy roll, are designs pressed into paper during manufacture and are visible when held up to light. Holograms (iv) are 3D laser-printed images used as a security feature on credit cards and passports.

Fluorescent fibers (ii) are embedded in some papers and emit light in response to certain wavelengths, used commonly in passport and currency papers.

76. The sequence of moleculer weight of primary explosive is:

(a) Mercury fulminate
(b) Lead azide
(c) Lead styphnate
(d) Silver azide
(e) Tetrazene
Choose the correct answer from the options given below:

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

The molecular weights of the primary explosives are as follows: Mercury fulminate (284.6 g/mol), Lead azide (291.2 g/mol), Lead styphnate (468.4 g/mol), Silver azide (251.8 g/mol), and Tetrazene (348.4 g/mol).

Therefore, the correct sequence from lowest to highest molecular weight would be Silver azide < Mercury fulminate < Lead azide < Tetrazene < Lead styphnate.

77. Arrange the following liquids in increasing order of its density.

(a) Kerosene
(b) Xylene
(c) Nitrobenzene
(d) Bromobenzene
Choose the correct answer from the option given below:

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

The densities of the various liquids at room temperature are as follows: Kerosene (0.81 g/cm³), Xylene (0.87 g/cm³), Nitrobenzene (1.20 g/cm³), Bromobenzene (1.50 g/cm³). Therefore, the correct sequence from lowest to highest density is Kerosene < Xylene < Nitrobenzene < Bromobenzene.

78. Normal sequence (minimal to severe) of fire progression is:

(a) Incipient
(b) Oxygen regulated smoldering
(c) Emergent smoldering
(d) Free burning
Choose the correct answer from the options given below:

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

79. The sequence of vapour pressure at 20°C of components of gasoline is:

(a) Toluene
(b) Iso-pentane
(c) Iso-hexane
(d) n-hexane
(e) n-heptane
Choose the correct answer from the options given below:

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

The vapor pressure of a substance, which is the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases at a given temperature, varies based on the substance.

In general, more volatile substances have higher vapor pressures. At 20°C, the sequence from lowest to highest vapor pressure would be Toluene < Iso-hexane < n-hexane < n-heptane < Isopentane.

80. Arrange the following, on the basis of characteristics around the entry wound, in sequence for determining the range of firing.

(a) Scorching
(b) Non-volatile products of combustion
(c) Unburnt powder grains
(d) Blackening
Choose the correct answer from the options given below: 

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

In firearm forensics, the pattern of residues around a gunshot wound can provide information about the distance from which  the weapon was fired. Scorching (caused by hot gases) indicates very close range.

Blackening (soot from powder combustion) can occur at a slightly further range. Unburnt powder grains are usually visible at an intermediate range, and non-volatile products of combustion (solid residues from the gunshot primer) can be deposited at longer ranges.

So, the sequence would be Scorching, Blackening, Unburnt powder grains, Nonvolatile products of combustion.