PrepAway - Latest Free Exam Questions & Answers

Which of the following is a light-sensitive chip used in most of today’s CCTV cameras?

Which of the following is a light-sensitive chip used in most of today’s CCTV cameras?

PrepAway - Latest Free Exam Questions & Answers

A.
Digital Light Processing

B.
Cathode ray tube

C.
Annunciator

D.
Charged-coupled devices

Explanation:
D: Most of the CCTV cameras in use today employ light-sensitive chips called charged-coupled devices (CCD). The CCD is an electrical circuit that receives
input light from the lens and converts it into an electronic signal, which is then displayed on the monitor. Images are focused through a lens onto the CCD chip
surface, which forms the electrical representation of the optical image. It is this technology that allows for the capture of extraordinary detail of objects and precise
representation, because it has sensors that work in the infrared range, which extends beyond human perception. The CCD sensor picks up this extra “data” and
integrates it into the images shown on the monitor to allow for better granularity and quality in the video. In addition to CCTV, CCDs are used in fax machines,
photocopiers, bar code readers, and even telescopes.
A is incorrect because Digital Light Processing (DLP) is a trademarked technology owned by Texas Instruments that is used in DLP front projectors and DLP
rear projection television. Images are created by tiny mirrors that are organized as a matrix on a semiconductor chip. The mirrors are toggled to reflect light,
thereby producing grayscales. Color is produced by a single-chip projector via a color wheel placed between the lamp and DLP chip or via individual light sources,
such as LEDs or LASERs. A three-chip DLP projector splits light from the lamp with a prism. Individual primary colors of light are routed to their own DLP chip.
They are then recombined and sent through the lens.
B is incorrect because a cathode ray tube (CRT) uses electrons to display an image. The CRT is a vacuum tube that contains an electron emitter and a
fluorescent screen. An electron beam is accelerated and deflected to create an image in the form of light given off by the fluorescent screen. Most of today’s
CCTVs use charged-coupled devices (CCDs) to allow for more granular information within an environment to be captured and shown on the monitor when
compared to the older CCTV technology that relied upon CRTs. CRTs have also been replaced in other applications by technologies that are lighter and less
fragile.
C is incorrect because an annunciator system can either “listen” for noise and activate electrical devices, such as lights, sirens, or CCTV cameras, or detect
movement. Instead of expecting a security guard to stare at a CCTV monitor for eight hours straight, the guard can carry out other activities and be alerted by an
annunciator if movement is detected on the screen. While monitor watching is a mentally deadening activity, the CCTV monitors must be watched to be effective.
An annunciator system is a solution to that.

One Comment on “Which of the following is a light-sensitive chip used in most of today’s CCTV cameras?


Leave a Reply