COMPUTER HARDWARE
STORAGE DEVICES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Red
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Green
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Blue
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Purple
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Detailed explanation-1: -In the case of CD-R, an infrared laser with a wavelength of 780 nanometers (nm) is employed, while DVD-R uses a red laser with a wavelength of 635 nm.
Detailed explanation-2: -Conventional optical technologies such as CD, DVD and magneto-optical (MO) drives write data using red lasers.
Detailed explanation-3: -Current CD lasers use gallium arsenide chips that emit near-infrared light. Over the last few years, however, researchers worldwide have been racing to commercialize blue lasers, which have a shorter wavelength than near-infrared light.
Detailed explanation-4: -A dvd/CD-ROM works with lasers because normal lightwaves are too big. With a DVD, you use a red laser beam to read and write the information. The information you write onto the disk can’t be smaller than the size of the beam.