Free CCTV Knowledge Questions and Answers — Questions and Answers

Question 1: Regarding cabling, UTP denotes:

Universal twisted pair
Universal twisted plenum
Unshielded twisted pair (Correct answer)
Unshielded twisted plenum

Correct answer: Unshielded twisted pair

UTP stands for Unshielded Twisted Pair. It is a common type of cabling used in telecommunications and computer networks, including some CCTV systems. UTP cables consist of pairs of wires twisted together to reduce electromagnetic interference, but unlike STP (Shielded Twisted Pair), they do not have an additional metallic shield.

Question 2: According to NFPA 70, what determines the type o insulation used on conductors in an installation?

Current of the circuit (Correct answer)
Length of conductor run
Type of raceway
Environment

Correct answer: Current of the circuit

According to NFPA 70 (National Electrical Code), the type of insulation used on conductors is primarily determined by the maximum operating temperature the insulation can safely withstand, which is directly related to the current flowing through the circuit. Higher currents generate more heat, requiring insulation with a higher temperature rating to prevent degradation and ensure safety. This is a critical factor in preventing electrical hazards.

Question 3: When pointing cameras toward highly illuminated regions, what feature assists to increase the quality of the image?

Backlight compensation (Correct answer)
Manual iris
Electric iris
IR illumination

Correct answer: Backlight compensation

Backlight compensation (BLC) is a crucial feature in CCTV cameras that improves image quality when a strong light source is behind the subject, causing the subject to appear dark or silhouetted. BLC works by increasing the exposure of the darker areas of the image, allowing details in the foreground to be more visible despite the bright background. This is essential for clear identification in challenging lighting conditions.

Question 4: What is meant by CIF is:

The grey scale of an image
The light output of a camera
A common resolution (Correct answer)
A common bandwidth requirement

Correct answer: A common resolution

CIF stands for Common Intermediate Format. It is a standard video resolution format, specifically 352x288 pixels (PAL) or 352x240 pixels (NTSC), commonly used in older CCTV systems and video conferencing. While it's a relatively low resolution by modern standards, it was widely adopted for its efficiency in storage and transmission, making it a 'common resolution' in the context of video surveillance.

Question 5: One feature of direct current is that it

Is produced by a transformer
Has a constant polarity (Correct answer)
Changes polarity
Cannot be stored

Correct answer: Has a constant polarity

Direct current (DC) is characterized by the flow of electrical charge in only one direction, meaning it has a constant polarity (one terminal is always positive, and the other is always negative). In contrast, alternating current (AC) periodically reverses its direction and polarity. This constant polarity is a fundamental defining feature of direct current.

Question 6: When a technician or salesperson adds content to a signed document or forges a customer's signature, what crimes are they committing?

Invasion of Privacy
Fraud (Correct answer)
Larceny
Indigent Interference

Correct answer: Fraud

When a technician or salesperson adds content to a signed document without authorization or forges a customer's signature, they are committing fraud. Fraud involves intentional deception for personal gain or to cause loss to another. These actions are deceitful and aim to misrepresent an agreement or obtain something under false pretenses, which are hallmarks of fraudulent activity and carry legal penalties.

Question 7: What is the acronym for CCD?

Charged Coupled Device (Correct answer)
Compressed Capture Device
Charged Compressed Device
Capacitive Coupled Device

Correct answer: Charged Coupled Device

CCD stands for Charged Coupled Device. It is a type of image sensor used in many digital cameras, including older CCTV cameras, camcorders, and scanners. CCD sensors convert light into electrical charges, which are then read out and processed to create a digital image, forming the core technology for capturing visual information.

Question 8: What setting on a meter should I use to measure VAC correctly?

V (Correct answer)
Ohms
V___
A___

Correct answer: V

To accurately measure VAC (Volts Alternating Current), a multimeter must be set to the 'V~' or 'VAC' function. The wavy line symbol (~) specifically denotes alternating current, ensuring the meter correctly interprets the oscillating nature of the voltage. Using this setting provides a precise reading of the AC voltage present in the circuit.

Question 9: In a power supply, a blown fuse typically signifies:

Too much current is being drawn (Correct answer)
Inadequate voltage
Too much resistance
The poser supply is too large

Correct answer: Too much current is being drawn

A fuse is a safety device designed to protect electrical circuits from excessive current. When a fuse blows, it indicates that the current flowing through the circuit has exceeded its rated capacity, causing the fuse's internal element to melt and break the circuit. This prevents damage to components or potential fire hazards due to overcurrent.

Question 10: There are two types of GSM and CDMA:

Internet networks
Two-way cellular networks
Cellular networks (Correct answer)
Public-switched telephone networks

Correct answer: Cellular networks

GSM (Global System for Mobile Communications) and CDMA (Code Division Multiple Access) are fundamental technologies that underpin modern cellular communication. They are different standards used by mobile network operators to transmit voice and data wirelessly. Both are integral components of cellular networks, enabling mobile phone services worldwide.

Question 11: What is the circuit's total current as depicted above? (This table is not visible.)

1.25A
1.58A
7.58A
0.125A
Need the table to better answer this question (Correct answer)

Correct answer: Need the table to better answer this question

To calculate the total current in an electrical circuit, essential information such as voltage, resistance, or individual currents in different branches is required. Without the 'depicted above' table, which presumably contains these necessary values, it is impossible to apply electrical laws like Ohm's Law (I=V/R) to determine the total current. Therefore, the question cannot be answered without the missing data.

Free CCTV Knowledge Questions and Answers

Regarding cabling, UTP denotes: