Defence Technology Archives

41. Which one of the following is not an essential component of Improvised

Which one of the following is not an essential component of Improvised Explosive Device (IED)?

Explosive

Detonator

Mechanical timer/Mechanical clock

Power source

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UPSC CISF-AC-EXE – 2021

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An Improvised Explosive Device (IED) fundamentally requires an explosive charge and a method to initiate it (detonator/initiator). Often, a power source is needed to enable the initiation mechanism, especially for electronic or timed devices. A mechanical timer or mechanical clock is one specific type of initiator delay mechanism, but it is not essential for *all* IEDs. An IED could use a different initiation method, such as a simple fuse, a pressure plate, a remote trigger, or a different type of timer (electronic, chemical). Therefore, the mechanical timer/clock is the least essential component among the options listed for a general IED definition.

The essential components of most IEDs are the explosive fill, the detonator, and an initiation system (which may include a power source and a trigger/timer mechanism). Different types of initiation systems exist; a mechanical timer is only one example of a delay mechanism.

IEDs are highly variable in design and components, limited only by the knowledge and materials available to the builder. The primary components enable the device to function as an explosive weapon: the explosive material provides the destructive energy, and the detonator/initiator causes the explosive to detonate. The method of triggering can vary widely, including command detonation (remote), time delay (mechanical, electronic, chemical), or victim-operated (pressure plate, tripwire).

42. What is the prescribed minimum explosive capacity of a Suspect Luggage

What is the prescribed minimum explosive capacity of a Suspect Luggage Containment Vehicle (SLCV) deployed at the airport ?

1 kg TNT (single use)

2 kg TNT (single use)

3 kg TNT (single use)

3 kg TNT (multiple use)

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UPSC CISF-AC-EXE – 2020

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The prescribed minimum explosive capacity of a Suspect Luggage Containment Vehicle (SLCV) deployed at the airport is 3 kg TNT (single use).

– SLCVs are specialized vehicles designed to safely contain and transport luggage or parcels suspected of containing explosives.
– The capacity is measured in terms of TNT equivalent, indicating the amount of explosive energy the containment structure can withstand.
– The specification ensures that the vehicle can mitigate the effects of a potential explosion within the contained item, protecting personnel and airport infrastructure.

– These standards are part of airport security protocols and regulations, often set by aviation security authorities like the Bureau of Civil Aviation Security (BCAS) in India or international bodies.
– The “single use” specification means the vehicle is designed to withstand one such event, and may need repair or replacement after containing an explosion of this magnitude.

43. Which one of the following BDDS equipments is a protection equipment ?

Which one of the following BDDS equipments is a protection equipment ?

Suspect Luggage Containment Vehicle (SLCV)

Stethoscope

Hook and Line Set

Explosive Vapour Detector

This question was previously asked in

UPSC CISF-AC-EXE – 2020

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The correct answer is A. The Suspect Luggage Containment Vehicle (SLCV) is a protection equipment used by Bomb Disposal and Detection System (BDDS) teams.

An SLCV is designed to safely transport a suspect explosive device away from a populated area to a disposal site or a safer location. It provides containment in case of accidental detonation during transport, thereby protecting personnel and the surrounding area.

Stethoscope, Hook and Line Set, and Explosive Vapour Detector are all tools used by BDDS teams, but they fall into different categories: Stethoscope is for listening for mechanical timers (detection/diagnosis), Hook and Line Set is for remote handling/manipulation (operation), and Explosive Vapour Detector is for detecting traces of explosives (detection). Only the SLCV is primarily a protective containment equipment.

44. What are MANPADS (Man-Portable Air-Defense Systems) ?

What are MANPADS (Man-Portable Air-Defense Systems) ?

Surface to Air Missiles

Air to Air Missiles

Portable Drones

None of the above

This question was previously asked in

UPSC CISF-AC-EXE – 2020

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MANPADS stands for Man-Portable Air-Defense System. These are shoulder-fired surface-to-air missiles (SAMs) designed to engage aircraft, typically helicopters or low-flying fixed-wing aircraft. They are portable by a single individual or a small team.

MANPADS are a type of surface-to-air missile designed for portability and use against aircraft.

MANPADS pose a significant threat to civil aviation, particularly during takeoff and landing phases when aircraft are at lower altitudes. Security measures at airports and surrounding areas often include counter-MANPADS strategies.

45. A Mini Remotely Operated Vehicle (MROV) should be capable of conductin

A Mini Remotely Operated Vehicle (MROV) should be capable of conducting EOD and surveillance inside

1. aircrafts.
2. passenger terminal buildings.
3. buildings and terminals.

Select the correct answer using the code given below :

1 and 2 only

2 and 3 only

1 and 3 only

1, 2 and 3

This question was previously asked in

UPSC CISF-AC-EXE – 2020

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A Mini Remotely Operated Vehicle (MROV) equipped for EOD and surveillance is designed to operate in various environments, including confined spaces and public areas, to investigate suspicious objects or conduct reconnaissance without risking human life. In an airport environment, suspicious items or potential threats could be located inside aircraft cabins, lavatories, or cargo holds (1), within the public areas of passenger terminals (2), or in other buildings, offices, or cargo facilities within the airport complex (3). A versatile MROV would be capable of navigating and conducting operations in all these locations.

MROVs are versatile tools used in EOD and surveillance across diverse environments, including those found within an airport.

MROVs used in security or EOD contexts are typically equipped with cameras, manipulators (arms) for interacting with objects, and sometimes other sensors like chemical detectors or disruptors. Their size and maneuverability make them suitable for accessing areas that may be dangerous or difficult for human personnel.

46. According to the prescribed specifications, the NLJD should be capable

According to the prescribed specifications, the NLJD should be capable of detecting ABCD circuit buried under dry soil up to a depth of at least

12 inches

18 inches

24 inches

36 inches

This question was previously asked in

UPSC CISF-AC-EXE – 2020

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Technical specifications for security equipment like NLJDs, particularly in regulated environments like airports or security forces, often prescribe minimum performance standards. While the exact standard referenced here requires specific documentation (likely from BCAS or procurement guidelines), detecting electronic components like ABCD circuits (possibly referring to standard electronic logic circuits used in timers or triggers) buried under dry soil is a typical application for NLJDs in search operations. A depth of at least 12 inches (approximately 30 cm) is a plausible minimum requirement for such detection capabilities in certain operational contexts. Without access to the specific official specification, it is difficult to confirm definitively, but 12 inches fits within the expected performance range for such equipment detecting small buried targets.

NLJDs are used for detecting buried or concealed electronic components. Performance specifications include detection depth.

The effective detection depth of an NLJD depends on various factors, including the power of the transmitter, the sensitivity of the receiver, the size and orientation of the target non-linear junction, and the composition and moisture content of the medium (soil, walls, etc.) it is searching through. Dry soil generally allows for better penetration compared to wet or highly conductive soil.

47. A non-linear junction detector is capable of detecting

A non-linear junction detector is capable of detecting

devices containing semi-conductors.

conventional explosives.

plastic and liquid explosives.

All of the above

This question was previously asked in

UPSC CISF-AC-EXE – 2020

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A Non-Linear Junction Detector (NLJD) is a device used to detect electronic components. It operates by transmitting a low-frequency signal and listening for harmonic responses characteristic of non-linear junctions found in semiconductors (diodes, transistors, integrated circuits). This allows it to locate electronic devices, such as listening devices, cameras, GPS trackers, or electronic components within an Improvised Explosive Device (IED), even if they are switched off.

NLJDs detect devices containing semiconductors, which are fundamental components of electronic circuits.

NLJDs are primarily used in technical surveillance counter-measures (TSCM) and Explosive Ordnance Disposal (EOD) or search operations to find hidden electronic devices or components of IEDs. They do not directly detect explosive materials themselves, but rather the electronic triggering or control components.

48. A highly sophisticated Multi-Zone DFMD is capable of detecting

A highly sophisticated Multi-Zone DFMD is capable of detecting

metallic items above a set threshold level.

metallic as well as non-metallic items.

metallic items, non-metallic items, as well as conventional explosives.

metallic items, non-metallic items, as well as all explosives including plastic and liquid explosives.

This question was previously asked in

UPSC CISF-AC-EXE – 2020

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A Door Frame Metal Detector (DFMD) works on the principle of electromagnetic induction. It detects changes in a magnetic field caused by the presence of metallic objects as a person passes through the frame. A Multi-Zone DFMD provides better spatial resolution, indicating the approximate height location of the detected metallic item. Regardless of sophistication or the number of zones, the core function of a DFMD is limited to detecting metallic items.

DFMDs are designed specifically for the detection of metals.

Detection of non-metallic items or explosives requires different technologies such as X-ray scanners (for density and shape), trace detectors (for chemical residues), or advanced imaging systems. While some modern screening systems might integrate multiple technologies, a device solely described as a Multi-Zone DFMD primarily performs metallic item detection.

49. The perimeter lighting at the airports should be provided on the

The perimeter lighting at the airports should be provided on the

inner side of the airport along the perimeter road and focusing towards the perimeter fencing/wall.

top of the perimeter wall focusing outside the perimeter.

top of the perimeter road and focusing inside the perimeter.

top of the watch-towers focusing outside the perimeter wall.

This question was previously asked in

UPSC CISF-AC-EXE – 2020

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Perimeter lighting at airports is crucial for detecting unauthorized entry into the airport area. The lighting should be positioned and directed to illuminate the area between the perimeter fence and the airport boundary or patrol road. This allows security personnel (often patrolling the perimeter road) and surveillance systems (like CCTV) to detect intruders approaching or attempting to breach the fence from the outside, or moving along the inner side of the fence.

The primary purpose of airport perimeter lighting is intrusion detection. Therefore, the lighting must effectively illuminate the vulnerable zone immediately adjacent to the perimeter barrier on the airport side.

Standard specifications for airport perimeter lighting require specific lux levels and uniformity across the illuminated area. The lights are typically mounted on poles along the perimeter road or just inside the fence, and are angled to cover the area between the road/mounting point and the fence line.

50. What is the prescribed height of the airport perimeter wall ?

What is the prescribed height of the airport perimeter wall ?

10 ft of wall with concertina coil overhang of 2 ft

8 ft of wall with concertina coil overhang of 1½ ft

9.5 ft of wall without any concertina coil

10 ft of wall or fence

This question was previously asked in

UPSC CISF-AC-EXE – 2020

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A commonly prescribed height for an airport perimeter barrier includes an 8 ft wall or fence topped with an additional 1½ ft of concertina coil overhang.

Airport perimeter barriers are designed to deter and prevent unauthorized entry. The height and design, including the use of difficult-to-climb elements like concertina wire, are standardized to provide a significant physical obstacle. The concertina coil effectively increases the overall barrier height and makes climbing much more hazardous.

While exact specifications might vary slightly based on national regulations and specific site requirements, the combination of a solid wall/fence of around 8 feet with an added overhang of sharp wire (like concertina coil) of about 1.5 to 2 feet is a widely adopted standard for airport perimeter security worldwide.