JKSSB Assistant Scientific Officer (Documents) 2026 Solved Question Paper

Question 1

Father of criminal investigation:

Accepted Answer

Option B: Alphonse Bertillon. In standard forensic examination curricula, Alphonse Bertillon is celebrated as the father of criminal identification/investigation for introducing anthropometry and systematic scientific crime scene processing. (Hans Gross is also historically recognized as the father of criminalistics).

Question 2

Who established comparison microscope as indispensible tool of modern firearms examination?

Accepted Answer

Option A: Calvin Goddard. Colonel Calvin Goddard pioneered the forensic comparison microscope to examine fired bullets and cartridge cases side-by-side, establishing forensic ballistics as a rigorous scientific discipline.

Question 3

Failure to substantiate the evidence's chain of custody may lead to serious questions regarding the:

Accepted Answer

Option C: Authenticity and integrity of evidence and examination of evidence.. A broken or undocumented chain of custody compromises the legal admissibility of evidence by casting doubt on its authenticity, integrity, and freedom from contamination or tampering.

Question 4

Reconstruction is done with the help of:

Accepted Answer

Option A: Physical evidences left behind at crime scene.. Crime scene reconstruction is the scientific process of determining the sequence of events at a crime scene through the holistic analysis, testing, and interpretation of physical evidence left at the scene.

Question 5

Match the following databases with their domain:
i. AFIS
ii. CODIS
iii. NIBIN
iv. PDQ
a. Database related to paints
b. Database related to fingerprints.
c. Database related to DNA
d. Database related to firearms
Options:

Accepted Answer

Option D: i-b, ii-c, iii-d, iv-a. AFIS is for fingerprints (i-b); CODIS is for DNA profiles (ii-c); NIBIN is the National Integrated Ballistic Information Network for firearms (iii-d); PDQ is the Paint Data Query database for automotive paints (iv-a). Thus, i-b, ii-c, iii-d, iv-a.

Question 6

Which are the duties of the first responding officer?
I. Write down the names of the witnesses and other persons who entered the crime scene.
II. Note who was at the crime scene when the officer arrived.
III. Mark and document the whole scene.
IV. Maintain chain of custody
Options:

Accepted Answer

Option A: I and II. The primary responsibilities of the first officer arriving at a crime scene are preserving life, securing the scene boundary, logging individuals present upon arrival (II), and recording names of all witnesses and entering personnel (I). Comprehensive mapping (III) and evidence custodial packaging (IV) are duties of forensic investigators.

Question 7

Arrange the following steps in the correct order for processing biological evidence at a homicide scene:
i. Collection of control samples
ii. Establishing entry and exit log
iii. Searching for biological stains using Alternate Light Source (ALS)
iv. Drying and packaging of wet biological exhibits.
v. Photography and documentation of biological evidence
vi. Presumptive testing for blood
Options:

Accepted Answer

Option D: ii, iii, v, vi, i, iv. The correct procedural protocol is: (ii) establish crime scene entry/exit log -> (iii) search for stains using ALS -> (v) in-situ photography/documentation -> (vi) perform presumptive chemical testing -> (i) collect substrate/control samples -> (iv) dry and package exhibits. Thus, ii, iii, v, vi, i, iv.

Question 8

Arrange in order from higher to lower officers in police system:
I. ADGP
II. SI
III. SSP
IV. ASI
Options:

Accepted Answer

Option A: I, III, II, IV. The hierarchical police rank structure from highest to lowest is: Additional Director General of Police (ADGP - I) > Senior Superintendent of Police (SSP - III) > Sub-Inspector (SI - II) > Assistant Sub-Inspector (ASI - IV). Thus, I, III, II, IV.

Question 9

Report of certain Government Scientific Experts is admissible under:

Accepted Answer

Option A: CrPC 293. Section 293 of the Code of Criminal Procedure (CrPC), 1973 (now Section 329 of BNSS, 2023) specifically governs the admissibility of reports by designated Government Scientific Experts (such as Directors of CFSL/FSL, Chemical Examiners, and Serologists) without requiring them to be called as witnesses in every case.

Question 10

Under which section of IEA the court may direct any person present in the court to write any words and figures for the purpose of comparison?

Accepted Answer

Option C: Section 73. Section 73 of the Indian Evidence Act, 1872 empowers the Court to direct any person present in the court to write any words or figures to enable the Court to compare the words or figures so written with any words or figures alleged to have been written by such person.

Question 11

Remunerated witness:

Accepted Answer

Option D: A paid witness.. A remunerated witness is defined as a paid witness who receives financial payment or remuneration for providing testimony or professional expert evidence in court.

Question 12

A judge of a court should compare the writing himself if the testimony of handwriting expert is not available.

Accepted Answer

Option A: True. Under Section 73 of the Indian Evidence Act, the court has the statutory power to compare disputed and admitted writings itself when no expert testimony is available, making the statement legally True.

Question 13

Consider the following statements:
Statement - I: Study of ethical dilemmas, choices and standards of application in a particular context, including occupations, professions and situation come under applied ethics.
Statement - II: In Forensic Science, the concept of ethics was given by Edmond Locard.
Options:

Accepted Answer

Option B: Only I is correct.. Statement I is correct because applied ethics specifically deals with practical ethical dilemmas and codes in specialized professions. Statement II is incorrect because Edmond Locard formulated the Principle of Exchange, not the concept of professional ethics.

Question 14

Consider the following statements:
Statement - I: Meta ethics study of moral thoughts and normal value.
Statement - II: Normative ethics concerned with criteria of what is morally right or wrong.
Options:

Accepted Answer

Option A: Both I and II are correct.. Both statements are correct definitions: Meta-ethics investigates the nature, foundation, and scope of moral concepts, while Normative ethics establishes practical rules and criteria for what constitutes morally right and wrong behavior.

Question 15

Match the following forensic laws with their proponents:
i. Law of Mutual Exchange
ii. Law of Individuality
iii. Law of Probability
Proponents:
a. Edmond Locard
b. Paul Kirk
c. Prof. Simon Newcomb
Options:

Accepted Answer

Option A: i-a, ii-b, iii-c. The Law of Mutual Exchange was stated by Edmond Locard (i-a); the fundamental Law of Individuality in forensic evidence was formalized by Paul L. Kirk (ii-b); and the Law of Probability in forensic identification was articulated by Simon Newcomb (iii-c). Thus, i-a, ii-b, iii-c.

Question 16

Correct sequence of examining witness in the court of law is:
I. Oath
II. Cross examination
III. Examination in chief
IV. Re-examination
Options:

Accepted Answer

Option A: I, III, II, IV. Under the Indian Evidence Act (Sections 137 & 138), a witness first takes Oath (I), followed by Examination-in-chief by the summoning party (III), Cross-examination by the adverse party (II), and Re-examination by the summoning party if permitted (IV). Thus, I, III, II, IV.

Question 17

The errors that arise on account of sheer carelessness of the observer are known as:

Accepted Answer

Option B: Gross errors. Gross errors are caused by human mistakes, sheer carelessness, improper instrument operation, or incorrect data recording by the observer. Systematic errors arise from faulty instruments, and random errors arise from uncontrollable fluctuations.

Question 18

Closeness of the measured value to the true value of the quantity is called:

Accepted Answer

Option A: Accuracy. Accuracy is defined as the degree of closeness of a measured experimental value to the accepted true or reference value. Precision refers to the repeatability or agreement among multiple independent measurements.

Question 19

The digits that are known reliably plus the first uncertain digit are known as:

Accepted Answer

Option B: Significant figures. In measurement science, significant figures are defined as all the digits in a number that are known with certainty plus one final digit that is estimated or uncertain.

Question 20

If the error in the measurement of radius of a sphere is 2%, then the error in the determination of the volume of the sphere will be:

Accepted Answer

Option B: 6%. The volume of a sphere is V = (4/3)*pi*r^3. The fractional error in volume is dV/V = 3*(dr/r). Therefore, percentage error in volume = 3 * 2% = 6%.

Question 21

Consider the following statements:
I. Light year and the year both measures time
II. Light year is the time light take to reach the earth from the sun
Choose the correct option:

Accepted Answer

Option B: Both I and II are false. Both statements are false: A light-year is a unit of astronomical distance (the distance light travels in one Julian year, ~9.46*10^15 m), not time. Sunlight takes approximately 8 minutes and 20 seconds to reach Earth, not a light-year.

Question 22

Consider the following statements:
Statement - I : Force cannot be added to pressure
Statement - II : Because their dimensions are different.
Choose the correct options:

Accepted Answer

Option A: Both are true. According to the Principle of Homogeneity of Dimensions, only physical quantities possessing identical dimensions can be added or subtracted. Force has dimensions [M L T^-2] whereas Pressure has [M L^-1 T^-2]; hence they cannot be added. Both statements are true.

Question 23

Match the following scientists/concepts with their corresponding values/discoveries:
i. Planck
ii. De Broglie
iii. Einstein
iv. Nuclear reactor
a. Heavy water
b. Photoelectric effect
c. Matter wave
d. 6.627*10^-27 erg·s
Choose the correct options:

Accepted Answer

Option A: i-d, ii-c, iii-b, iv-a. Planck's constant is 6.627*10^-27 erg·s (i-d); De Broglie proposed matter waves (ii-c); Einstein explained the photoelectric effect (iii-b); heavy water is used as a moderator in nuclear reactors (iv-a). Thus, i-d, ii-c, iii-b, iv-a.

Question 24

Arrange the following in ascending order of their size:
I. Electron
II. Red blood cells
III. Proton
IV. A cell
Choose the correct options:

Accepted Answer

Option A: I<III<II<IV. In ascending order of physical dimension: Electron (< 10^-18 m) < Proton (~10^-15 m) < Red Blood Cell (~6-8 micrometers) < Typical large biological cell (~10-100 micrometers). Thus, I < III < II < IV.

Question 25

The actual path traversed by the object in the given time is known as:

Accepted Answer

Option B: Path length. Path length (distance) is the total length of the actual trajectory traversed by an object during its motion. In contrast, displacement is the shortest directed vector between initial and final positions.

Question 26

The product of mass of the body and its velocity is called:

Accepted Answer

Option B: Linear momentum. Linear momentum (p) of an object is defined by Newton's laws as the product of its mass (m) and its linear velocity (v), i.e., p = m * v.

Question 27

The forces which are acting at the same point are:

Accepted Answer

Option A: Concurrent forces. Forces whose lines of action all intersect at a single common point in a system are defined as concurrent forces.

Question 28

The force which acts between two bodies in contact that opposes relative motion is called:

Accepted Answer

Option B: Frictional force. Frictional force is the tangential contact force exerted between two interacting surfaces in physical contact that opposes their relative sliding or rolling motion.

Question 29

Consider the following statements:
I. Electric current is associated with the flow of electrons.
II. Electric current is associated with the flow of protons.
III. Electric current is a scalar quantity
Choose the correct options:

Accepted Answer

Option C: Both I and III. Statement I is true because conduction in conductors occurs via mobile electrons. Statement II is false because bound protons in atomic nuclei do not flow in electric circuits. Statement III is true because current obeys scalar algebraic addition laws, not vector algebra. Thus, Both I and III are correct.

Question 30

Consider the following statements:
I. Current is always proportional to the voltage
II. The above statement was stated by Ohm in Ohm's law
III. Resistance always supports the flow of electric current
Choose the correct option:

Accepted Answer

Option A: Both I and II. Statements I and II correctly state Ohm's law (V = IR), which establishes that current is directly proportional to applied voltage across an ohmic conductor at constant physical conditions. Statement III is false because electrical resistance opposes the flow of electric current.

Question 31

Match the following physical concepts:
i. Right hand rule
ii. Electric current
iii. Magnetic field
iv. Magnetic field due to current
a. Scalar quantity
b. Vector quantity
c. Direction of force
d. Electromagnetism
Options:

Accepted Answer

Option B: i-c, ii-a, iii-b, iv-d. The right-hand rule determines the direction of magnetic force/field (i-c); electric current is a scalar quantity (ii-a); magnetic field is a vector quantity (iii-b); magnetic field produced by current represents electromagnetism (iv-d). Thus, i-c, ii-a, iii-b, iv-d.

Question 32

Arrange in ascending order of their limit:
I. Static friction
II. Rolling friction
III. Kinetic friction
Options:

Accepted Answer

Option A: II<III<I. For any given pair of surfaces, rolling friction is the weakest, followed by kinetic (sliding) friction, with limiting static friction having the highest magnitude. In ascending order: Rolling (II) < Kinetic (III) < Static (I).

Question 33

Which rays of electromagnetic spectrum may damage the retina of our eyes?

Accepted Answer

Option B: UV rays. Ultraviolet (UV) radiation (particularly UV-A and intense UV blue wavelengths) can penetrate ocular media to induce photochemical damage and macular photoretinitis in the retina.

Question 34

The radius of the cross section of the laser beam is called:

Accepted Answer

Option A: Spot size. The radius of the cross-sectional waist or circular profile of a laser beam (often defined at the 1/e^2 intensity level) is termed the beam spot size (w0).

Question 35

In Nd:YAG, YAG stands for:

Accepted Answer

Option C: Yttrium aluminium garnet. In the Nd:YAG solid-state laser, YAG stands for Yttrium Aluminium Garnet (chemical formula Y3Al5O12), which serves as the host crystal doped with neodymium ions (Nd3+).

Question 36

Typical output power in a continuous wave argon ion laser is of:

Accepted Answer

Option C: 3-5 w. Standard continuous-wave (CW) argon-ion gas lasers widely used in forensic spectroscopy and latent print detection typically generate continuous output power in the 3 to 5 Watt range across visible lines (488 nm and 514.5 nm).

Question 37

Consider the following statements regarding carbon dioxide molecule:
I. Molecule of CO2 can vibrate in three independent modes of vibration.
II. Those modes are symmetric stretch, bending, and asymmetric stretch modes.
III. These modes are not characterized by the definite frequency of vibration.
Which of the following statements is/are correct?

Accepted Answer

Option B: Both I and II. CO2 is a linear molecule possessing three fundamental vibrational frequency modes: symmetric stretching, doubly degenerate bending, and asymmetric stretching (Statements I and II are correct). Statement III is false because each normal vibrational mode possesses an exact, well-defined characteristic quantum frequency.

Question 38

The following are the characteristics of laser diode:
I. In a plot of laser diode current characteristics, current is on x axis and light output is on y axis.
II. Laser oscillation begins when output reaches threshold.
III. On crossing the threshold the emission becomes coherent.
Choose the correct options:

Accepted Answer

Option D: All I, II and III. In the standard L-I (light vs. current) characteristic curve of a laser diode, drive current is on the x-axis and optical power is on the y-axis (I). Lasing oscillation initiates at threshold current (II), above which stimulated emission produces highly coherent laser light (III). All three are correct.

Question 39

Match the following laser types with their characteristics/materials:
i. Ti: Sapphire
ii. CO2 laser
iii. Nd:YAG laser
iv. Nd: glass laser
a. Y3Al5O12
b. Titanium sapphire laser
c. Vibrational modes
d. Four level laser system
Options:

Accepted Answer

Option A: i-b, ii-c, iii-a, iv-d. Ti:Sapphire is a titanium-doped sapphire laser (i-b); CO2 laser operates on molecular vibrational modes of carbon dioxide (ii-c); Nd:YAG uses Y3Al5O12 crystal host (iii-a); and Nd:glass operates as a classic four-level laser system (iv-d). Thus, i-b, ii-c, iii-a, iv-d.

Question 40

Arrange in correct sequence of population distribution in the energy levels of a four-level laser system in thermal equilibrium:

Accepted Answer

Option B: N4<N3<N2<N1. According to the Boltzmann distribution in thermal equilibrium, the population density of quantum states decreases exponentially with increasing energy (E1 < E2 < E3 < E4), meaning ground state N1 has the highest population and highest level N4 has the lowest: N4 < N3 < N2 < N1.

Question 41

According to Pauli's Exclusion Principle:

Accepted Answer

Option D: Spin of two electrons in the same orbit is opposite to each other.. Pauli's Exclusion Principle dictates that no two electrons in an atom can have the same set of four quantum numbers. Therefore, two electrons sharing the same orbital must have opposite (antiparallel) spins (+1/2 and -1/2).

Question 42

Raman lines are expressed as:

Accepted Answer

Option A: Wave number. Raman spectral shifts are universally plotted and reported as wavenumber shifts (in units of cm^-1) relative to the excitation laser frequency.

Question 43

Substituents that delocalize the pi-electrons, often enhance fluorescence because:

Accepted Answer

Option B: They tend to increase the transition probability between lowest excited singlet state and the ground state.. Extended pi-electron delocalization enhances molecular rigidity and increases the radiative transition probability (rate constant of fluorescence emission) from the lowest excited singlet state (S1) back to the ground state (S0).

Question 44

Luminescence is the method for:

Accepted Answer

Option C: Quantitative analysis and Qualitative analysis. Luminescence spectroscopy provides both qualitative identification (via characteristic emission spectra and peak wavelengths) and sensitive quantitative analysis (as emitted luminescence intensity is directly proportional to analyte concentration).

Question 45

Which of the following are the limitations of Beer-Lambert's law?
I. Concentration must be lower
II. Radiation must have higher bandwidth
III. Radiation source must be monochromatic
IV. Does not consider factors other than thickness and concentration
Choose the correct options:

Accepted Answer

Option D: All of these. Beer-Lambert's law exhibits deviations at high concentrations (>0.01 M), polychromatic/broadband radiation introduces non-linearities, strictly requires monochromatic light, and ignores refractive index shifts and chemical equilibria. Thus, all listed factors represent foundational limitations.

Question 46

Consider the following statements regarding Atomic Absorption Spectroscopy (AAS):
I. Atomic absorption is a specific technique.
II. In atomic absorption spectroscopy, hollow cathode lamp is widely used.
Choose the correct option:

Accepted Answer

Option A: Both I and II are correct. Atomic Absorption Spectroscopy is an element-specific analytical technique because atomic absorption lines are extremely narrow (~0.002 nm), and hollow cathode lamps containing the target element cathode are standard narrow line sources. Both statements are correct.

Question 47

To calculate the concentration of unknown solution in atomic absorption spectroscopy using the linear calibration equation A = mc, match the following:
i. A
ii. m
iii. c
a. Concentration
b. Absorbance
c. Slope
d. Mass of electron
Choose the correct option:

Accepted Answer

Option B: i-b, ii-c, iii-a. In the calibration equation A = mc, A represents measured Absorbance (i-b), m is the sensitivity slope of the calibration curve (ii-c), and c is the analyte Concentration (iii-a). Thus, i-b, ii-c, iii-a.

Question 48

Arrange the following regions in ascending order of their wavenumber in the IR region of electromagnetic spectrum:
I. 12500 to 4000 cm^-1
II. 4000 to 400 cm^-1
III. 400 to 20 cm^-1
IV. 4000 to 20 cm^-1
Choose the correct option:

Accepted Answer

Option A: I<II<III. The infrared spectrum is traditionally divided into Near-IR (12,500 to 4,000 cm^-1 - I), Mid-IR (4,000 to 400 cm^-1 - II), and Far-IR (400 to 20 cm^-1 - III). Option A represents the standard sequence I, II, III across these designated spectral zones.

Question 49

Wavelength selection in spectroscopy is NOT done by:

Accepted Answer

Option B: Detectors. Detectors convert optical energy into electrical signals. Wavelength isolation or selection is accomplished by wavelength selectors, which include optical filters, diffraction gratings, prisms, and monochromators.

Question 50

In IR spectroscopy, mostly the spectral range used is:

Accepted Answer

Option C: 4000-500 cm^-1. The mid-infrared region spanning 4000 to 500 cm^-1 (or 4000 to 400 cm^-1) is the most extensively utilized range in chemical and forensic document analysis for functional group and fingerprint identification.

Question 51

A thermopile consists of ........ thermocouples connected in series:

Accepted Answer

Option C: Often 6. In classic infrared thermal detectors, a thermopile typically consists of multiple thermocouples (often 6 or more) connected in series to amplify the thermoelectric Seebeck voltage output.

Question 52

Average sample desired for qualitative analysis in IR spectroscopy:

Accepted Answer

Option C: 1 milligram. In standard qualitative transmission infrared spectroscopy (such as the preparation of a 1% KBr pellet or Nujol mull), approximately 1 milligram of sample is routinely required.

Question 53

Consider the following statements:
I. Fundamental bands are the primary absorption bands.
II. Overtone bands occur at multiples of fundamental bands.
III. Combination bands occur at wavelengths that are sum or difference of two or more fundamental bands.
Choose the correct option:

Accepted Answer

Option A: I, II and III are correct. All three statements correctly describe vibrational transitions: Fundamental bands involve v=0 to v=1 (I); Overtones appear near integer multiples 2v, 3v (II); and Combination bands arise from simultaneous excitation of multiple vibrational modes (v1 + v2 or v1 - v2) (III).

Question 54

Consider the following statements:
I. IR spectrometry provides far more complex pattern.
II. Because different materials have distinctly different IR spectra.
Choose the correct option:

Accepted Answer

Option A: Both I and II are correct and II is the correct explanation of I. Polyatomic molecules generate highly complex, intricate infrared spectra due to numerous vibrational modes and coupling (fingerprint region), which makes the spectrum unique for different substances. Both statements are correct, and II explains the forensic specificity of I.

Question 55

Match the following optical phenomena:
i. IR
ii. Visible light
iii. Dispersion
iv. Luminescence
a. VIBGYOR
b. Fingerprint region
c. Splitting of white light
d. Emission of light of complementary color
Choose the correct option:

Accepted Answer

Option A: i-b, ii-a, iii-c, iv-d. IR spectroscopy is characterized by the fingerprint region (i-b); Visible light spans the VIBGYOR rainbow spectrum (ii-a); Dispersion is the splitting of white light into its component colors (iii-c); Luminescence involves the emission of light (iv-d). Thus, i-b, ii-a, iii-c, iv-d.

Question 56

Arrange the following components of a typical spectrophotometer in correct sequence:
I. Radiation source
II. Monochromator
III. Sample cell
IV. Detector
V. Recorder
Choose the correct option:

Accepted Answer

Option A: I Monochromator (II) -> Sample cell (III) -> Detector (IV) -> Readout device/Recorder (V). Thus, I < II < III < IV < V.

Question 57

Most forensic work requires a maximum magnification of:

Accepted Answer

Option B: 450x. In standard forensic examination literature (Saferstein, Criminalistics), most forensic physical evidence and document microscopic examinations require a magnification of up to 400x to 450x.

Question 58

Empty magnification in compound microscope is referred to:

Accepted Answer

Option C: No additional detail beyond 1000x. Empty magnification refers to increasing the magnification of an optical microscope beyond the resolution limit of visible light (~1000x numerical aperture), which enlarges the image without revealing any additional resolved detail.

Question 59

Scanning Electron Microscope provides:

Accepted Answer

Option D: High magnification, high resolution and elemental composition.. Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (SEM-EDX) provides high magnification, extraordinary depth of field and high spatial resolution, and simultaneous non-destructive elemental composition analysis.

Question 60

In Atomic Absorption Spectrometer, PMT acts as:

Accepted Answer

Option B: Input transducer. In instrument classification, the PMT acts as an input transducer (detector), which receives optical radiation from the monochromator and converts the radiant energy into an electrical signal.

Question 61

In SEM, which of the following statements are NOT true for secondary electrons?
I. Strike the object releasing other electrons
II. Strike the object and then reflect off the surface
III. Are emitted when beam of primary electrons strike the object
IV. Are emitted by the nucleus of the various elements when the object is struck by a beam of x-rays
Choose the correct option:

Accepted Answer

Option C: I, II and IV are correct. Statement III is the only accurate statement describing secondary electrons (they are emitted from the specimen surface due to inelastic scattering of the primary electron beam). Statements I, II, and IV are false/not true, making option C (I, II and IV) the correct selection of untrue statements.

Question 62

Consider the following statements:
Statement - I : In PMT, magnitude of signal is increased.
Statement - II : It is due to the action of dynode.
Choose the correct option:

Accepted Answer

Option A: Both I and II are correct and II is the correct explanation of I. In a Photomultiplier Tube (PMT), the electron signal is multiplied exponentially by secondary electron emission as photoelectrons cascade across successive dynodes held at increasing potentials. Thus, both statements are true and II explains I.

Question 63

Match the following instruments with their characteristic detectors:
i. X-rays
ii. NMR
iii. Visible spectrophotometer
iv. IR spectroscopy
a. Crossed coil
b. Bolometer
c. Silicon lithium drifted detector
d. Photovoltaic cell
Choose the correct option:

Accepted Answer

Option B: i-c, ii-a, iii-d, iv-b. X-ray spectroscopy uses Si(Li) solid-state semiconductor detectors (i-c); NMR uses radiofrequency crossed coils or tuned probe coils (ii-a); Visible spectrophotometry uses photovoltaic/photodiode cells (iii-d); and IR spectroscopy uses thermal bolometer detectors (iv-b). Thus, i-c, ii-a, iii-d, iv-b.

Question 64

Arrange the following components of a Thermal Conductivity Detector (TCD) in sequence:
I. Gas flow in
II. Gas flow out
III. Block
IV. Filament
Choose the correct option:

Accepted Answer

Option A: I<III<IV<II. In a TCD cell, the effluent gas enters through the inlet port (I), passes into the heated metallic block cavity (III), flows over the electrically heated tungsten-rhenium filament (IV), and exits through the outlet (II). Thus, I < III < IV < II.

Assistant Scientific Officer (Documents)2026

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JKSSB — Assistant Scientific Officer (Documents) (2026)

Father of criminal investigation:

Who established comparison microscope as indispensible tool of modern firearms examination?

Failure to substantiate the evidence's chain of custody may lead to serious questions regarding the:

Reconstruction is done with the help of:

Match the following databases with their domain:\ni. AFIS\nii. CODIS\niii. NIBIN\niv. PDQ\na. Database related to paints\nb. Database related to fingerprints.\nc. Database related to DNA\nd. Database related to firearms\nOptions:

Which are the duties of the first responding officer?\nI. Write down the names of the witnesses and other persons who entered the crime scene.\nII. Note who was at the crime scene when the officer arrived.\nIII. Mark and document the whole scene.\nIV. Maintain chain of custody\nOptions:

Arrange in order from higher to lower officers in police system:\nI. ADGP\nII. SI\nIII. SSP\nIV. ASI\nOptions:

Report of certain Government Scientific Experts is admissible under:

Under which section of IEA the court may direct any person present in the court to write any words and figures for the purpose of comparison?

Remunerated witness:

A judge of a court should compare the writing himself if the testimony of handwriting expert is not available.

Consider the following statements:\nStatement - I: Meta ethics study of moral thoughts and normal value.\nStatement - II: Normative ethics concerned with criteria of what is morally right or wrong.\nOptions:

Match the following forensic laws with their proponents:\ni. Law of Mutual Exchange\nii. Law of Individuality\niii. Law of Probability\nProponents:\na. Edmond Locard\nb. Paul Kirk\nc. Prof. Simon Newcomb\nOptions:

Correct sequence of examining witness in the court of law is:\nI. Oath\nII. Cross examination\nIII. Examination in chief\nIV. Re-examination\nOptions:

The errors that arise on account of sheer carelessness of the observer are known as:

Closeness of the measured value to the true value of the quantity is called:

The digits that are known reliably plus the first uncertain digit are known as:

If the error in the measurement of radius of a sphere is 2%, then the error in the determination of the volume of the sphere will be:

Consider the following statements:\nI. Light year and the year both measures time\nII. Light year is the time light take to reach the earth from the sun\nChoose the correct option:

Consider the following statements:\nStatement - I : Force cannot be added to pressure\nStatement - II : Because their dimensions are different.\nChoose the correct options:

Match the following scientists/concepts with their corresponding values/discoveries:\ni. Planck\nii. De Broglie\niii. Einstein\niv. Nuclear reactor\na. Heavy water\nb. Photoelectric effect\nc. Matter wave\nd. 6.627*10^-27 erg·s\nChoose the correct options:

Arrange the following in ascending order of their size:\nI. Electron\nII. Red blood cells\nIII. Proton\nIV. A cell\nChoose the correct options:

The actual path traversed by the object in the given time is known as:

The product of mass of the body and its velocity is called:

The forces which are acting at the same point are:

The force which acts between two bodies in contact that opposes relative motion is called:

Consider the following statements:\nI. Electric current is associated with the flow of electrons.\nII. Electric current is associated with the flow of protons.\nIII. Electric current is a scalar quantity\nChoose the correct options:

Consider the following statements:\nI. Current is always proportional to the voltage\nII. The above statement was stated by Ohm in Ohm's law\nIII. Resistance always supports the flow of electric current\nChoose the correct option:

Match the following physical concepts:\ni. Right hand rule\nii. Electric current\niii. Magnetic field\niv. Magnetic field due to current\na. Scalar quantity\nb. Vector quantity\nc. Direction of force\nd. Electromagnetism\nOptions:

Arrange in ascending order of their limit:\nI. Static friction\nII. Rolling friction\nIII. Kinetic friction\nOptions:

Which rays of electromagnetic spectrum may damage the retina of our eyes?

The radius of the cross section of the laser beam is called:

In Nd:YAG, YAG stands for:

Typical output power in a continuous wave argon ion laser is of:

Match the following laser types with their characteristics/materials:\ni. Ti: Sapphire\nii. CO2 laser\niii. Nd:YAG laser\niv. Nd: glass laser\na. Y3Al5O12\nb. Titanium sapphire laser\nc. Vibrational modes\nd. Four level laser system\nOptions:

Arrange in correct sequence of population distribution in the energy levels of a four-level laser system in thermal equilibrium:

According to Pauli's Exclusion Principle:

Raman lines are expressed as:

Substituents that delocalize the pi-electrons, often enhance fluorescence because:

Luminescence is the method for:

Which of the following are the limitations of Beer-Lambert's law?\nI. Concentration must be lower\nII. Radiation must have higher bandwidth\nIII. Radiation source must be monochromatic\nIV. Does not consider factors other than thickness and concentration\nChoose the correct options:

Consider the following statements regarding Atomic Absorption Spectroscopy (AAS):\nI. Atomic absorption is a specific technique.\nII. In atomic absorption spectroscopy, hollow cathode lamp is widely used.\nChoose the correct option:

To calculate the concentration of unknown solution in atomic absorption spectroscopy using the linear calibration equation A = mc, match the following:\ni. A\nii. m\niii. c\na. Concentration\nb. Absorbance\nc. Slope\nd. Mass of electron\nChoose the correct option:

Arrange the following regions in ascending order of their wavenumber in the IR region of electromagnetic spectrum:\nI. 12500 to 4000 cm^-1\nII. 4000 to 400 cm^-1\nIII. 400 to 20 cm^-1\nIV. 4000 to 20 cm^-1\nChoose the correct option:

Wavelength selection in spectroscopy is NOT done by:

In IR spectroscopy, mostly the spectral range used is:

A thermopile consists of ........ thermocouples connected in series:

Average sample desired for qualitative analysis in IR spectroscopy:

Consider the following statements:\nI. Fundamental bands are the primary absorption bands.\nII. Overtone bands occur at multiples of fundamental bands.\nIII. Combination bands occur at wavelengths that are sum or difference of two or more fundamental bands.\nChoose the correct option:

Consider the following statements:\nI. IR spectrometry provides far more complex pattern.\nII. Because different materials have distinctly different IR spectra.\nChoose the correct option:

Match the following optical phenomena:\ni. IR\nii. Visible light\niii. Dispersion\niv. Luminescence\na. VIBGYOR\nb. Fingerprint region\nc. Splitting of white light\nd. Emission of light of complementary color\nChoose the correct option:

Arrange the following components of a typical spectrophotometer in correct sequence:\nI. Radiation source\nII. Monochromator\nIII. Sample cell\nIV. Detector\nV. Recorder\nChoose the correct option:

Most forensic work requires a maximum magnification of:

Empty magnification in compound microscope is referred to:

Scanning Electron Microscope provides:

In Atomic Absorption Spectrometer, PMT acts as:

Consider the following statements:\nStatement - I : In PMT, magnitude of signal is increased.\nStatement - II : It is due to the action of dynode.\nChoose the correct option:

Match the following instruments with their characteristic detectors:\ni. X-rays\nii. NMR\niii. Visible spectrophotometer\niv. IR spectroscopy\na. Crossed coil\nb. Bolometer\nc. Silicon lithium drifted detector\nd. Photovoltaic cell\nChoose the correct option:

Arrange the following components of a Thermal Conductivity Detector (TCD) in sequence:\nI. Gas flow in\nII. Gas flow out\nIII. Block\nIV. Filament\nChoose the correct option:

Volatile inorganic poisons are analyzed by using:

Separation efficiency of capillary electrophoresis and other high-resolution techniques is modeled by:

In Micellar Electrokinetic Capillary Chromatography (MEKC), separation is based on:

In normal phase TLC plate, silica gel GF254 as stationary phase under UV light:

Consider the following statements:\nStatement - I: Derivatization prior to gas chromatography is often desirable.\nStatement - II: It improves thermal stability of compounds, particularly those containing polar functional groups.\nOptions:

Choose the correct order of setup of a High-Performance Liquid Chromatography (HPLC) system:\nI. Solvent reservoir\nII. Recorder\nIII. Pump\nIV. Guard column\nV. Detector\nVI. Injector\nVII. Analytical Column\nOptions:

Consider the following statements:\nStatement - I: In electrophoresis, rate of migration is directly proportional to the current.\nStatement - II: Electrophoresis is used to identify the enzymes in blood samples.\nOptions:

Match the following techniques with their operational principles/components:\ni. HPLC\nii. Electrophoresis\niii. GC\niv. Chromatography\na. Movement of charged ions\nb. Refractive index monitor\nc. Pigment separation\nd. Electron capture\nOptions:

Statistics deals with:

Chi-square distribution is useful to test the:

To test hypothesis about proportion of items in a class, the usual test is:

Paired t-test is applicable when the observations in the two samples are:

Chi-square test can be used:\nI. As a parametric test\nII. As a test of goodness of fit\nIII. As a test of independence.\nOptions:

Which type of photography is used to decipher typewritten text on charred documents?

An opinion of non-authenticity is justified by:

Paper is at its best when it has ........% of moisture. If the moisture reduces paper becomes brittle.

Guided signature is devoid of:

Arrange in correct chronological order from older to latest:\nI. CrPC\nII. IEA\nIII. IPC\nIV. NDPS\nOptions: