Free CCTV Knowledge Questions and Answers

Question 1

Regarding cabling, UTP denotes:

Accepted Answer

Unshielded twisted pair

Answer

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?

Accepted Answer

Current of the circuit

Answer

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?

Accepted Answer

Backlight compensation

Answer

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:

Accepted Answer

A common resolution

Answer

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

Accepted Answer

Has a constant polarity

Answer

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.

CCTV - Closed Circuit Television Practice Test

CCTV - Closed Circuit Television Practice Test

Free CCTV Knowledge Questions and Answers