COMPUTER FUNDAMENTALS

COMPUTER HARDWARE

STORAGE DEVICES

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
What do optical drives use to read data on CDs or DVDs?
A
Flash Memory
B
Metallic Tape
C
Magnetic Tape
D
Laser
Explanation: 

Detailed explanation-1: -Optical disks rely on a red or blue laser to record and read data. Most of today’s optical disks are flat, circular and 12 centimeters in diameter. Data is stored on the disk in the form of microscopic data pits and lands.

Detailed explanation-2: -laser technology Tiny, inexpensive semiconductor lasers read data from a growing variety of optical compact disc formats to play music, display video recordings, and read computer software.

Detailed explanation-3: -The lasers uses in DVD players operate at a wavelength of 650 nm (instead of 780 nm in a CD). 650 nm is visible for the human eye and corresponds to a red color: you’ve probably noticed that there is a red light shining onto the DVD surface inside the player.

Detailed explanation-4: -Blu-ray. The Blu-ray disk has emerged as clear leader in today’s optical storage market. Unlike CDs and DVDs, which use a red laser to read and write data, a Blu-ray disk uses a blue laser, which dramatically increases capacities and data transfer rates over CDs and DVDs.

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