Explain optical disks in detail.

1.	Explain optical disks in detail.
Answer» 1. CD ROM: Compact disks are known as optical storage devices. A compact disc is a thin, circular disc of metal and plastic about 12cm (just over 4!4 inches) in diameter. It’s actually made up of three layers. Most of a CD is made from a tough, brittle plastic called polycarbonate. Sandwiched in the middle there is a thin layer of aluminum. Finally, on top of the aluminum, is a protective layer of lacquer. There is a shiny side and dull side. The dull side usually has a label on it telling you what’s on the CD; the shiny side is the important part. It’s shiny so that a laser beam can bounce off the disc and read the information stored on it. A CD can store around 650 MB of data. It comes in two main forms namely CD-ROM CD Read-Only memory in which data can only be written once and CD-RW CD ReWriteable means data new can be saved on the disk over and over again. 2. Digital Versatile Disk (DVD): A DVD is similar to a CD in that it is an optical device and that a laser is used to store and read the data. A single layer DVD can store about 4.7GB of data and a double-layer DVD can hold over 9 GB data. DVDs do not work on CD drives but DVD drives can read CDs. There is no single standard of DVD. They can be easily damaged by breaking or scratching. 3. Blu ray dies: The Blu-ray is an optical storage unit and its technology is identical to CDs and DVDs. But the difference is a blue laser is used in Blu-ray disc instead of the red lasers that were used in the earlier versions. The BluRay standard was established to hold a standard-length movie in HDTV format, or high-definition television. Such movies are displayed in significantly higher resolution and therefore they require much more storage space. A standard Blu-ray disc holds 27GB (gigabytes) of information which is about 40 times the amount of data that a CD can hold. Blue lasers have a shorter wavelength (450 nano meters) than red lasers (650 nano meters), and therefore the beam can be focused on a smaller area which means that more data can be packed on an identically sized disc.

Answer»

1. CD ROM:

Compact disks are known as optical storage devices. A compact disc is a thin, circular disc of metal and plastic about 12cm (just over 4!4 inches) in diameter. It’s actually made up of three layers. Most of a CD is made from a tough, brittle plastic called polycarbonate. Sandwiched in the middle there is a thin layer of aluminum. Finally, on top of the aluminum, is a protective layer of lacquer. There is a shiny side and dull side. The dull side usually has a label on it telling you what’s on the CD; the shiny side is the important part. It’s shiny so that a laser beam can bounce off the disc and read the information stored on it.

A CD can store around 650 MB of data. It comes in two main forms namely CD-ROM CD Read-Only memory in which data can only be written once and CD-RW CD ReWriteable means data new can be saved on the disk over and over again.

2. Digital Versatile Disk (DVD):

A DVD is similar to a CD in that it is an optical device and that a laser is used to store and read the data. A single layer DVD can store about 4.7GB of data and a double-layer DVD can hold over 9 GB data. DVDs do not work on CD drives but DVD drives can read CDs. There is no single standard of DVD. They can be easily damaged by breaking or scratching.

3. Blu ray dies:

The Blu-ray is an optical storage unit and its technology is identical to CDs and DVDs. But the difference is a blue laser is used in Blu-ray disc instead of the red lasers that were used in the earlier versions. The BluRay standard was established to hold a standard-length movie in HDTV format, or high-definition television. Such movies are displayed in significantly higher resolution and therefore they require much more storage space.

A standard Blu-ray disc holds 27GB (gigabytes) of information which is about 40 times the amount of data that a CD can hold. Blue lasers have a shorter wavelength (450 nano meters) than red lasers (650 nano meters), and therefore the beam can be focused on a smaller area which means that more data can be packed on an identically sized disc.

Explain optical disks in detail.

Discussion

No Comment Found

Related InterviewSolutions

Reply to Comment