Which of the following are not true about optical disks?
1. They are available in fully erasable form.
2. They can store pictures as well as text.
3. They are read from and written to by laser beams.
Hi,
I will answer your query here one by one according to the order of your question.
Which of the following are not true about optical disks?
1. They are available in fully erasable form.
Ans: Yes, there are available erasable form of optical disk, all you need is to look on the RW symbol written on its label.
2. They can store pictures as well as text.
Ans: Optical disk can store all type of digital data, in the form of audio, pictures, text, application.
3. They are read from and written to by laser beams.
Ans: Yes, it uses the technology of laser light or electromagnetic waves or near the visible light spectrum as a way to of reading and writing data to an optical discs.
To summarize, all your questions here are true, I don't see any false statement in it.
The first sentence is not true if that points to optical discs in general. Optical discs are available in read-only memory or ROM and rewritable or RW. That’s why there are CD-R and CD-RW discs for the CD type and DVD-R and DVD-RW for the DVD type. The “R” in “CD-R” means “recordable”. It means you can write or burn data to the disc.
Recordable discs are limited only to writing data. Once the data or files are burned to the disc, they can no longer be deleted or erased from the disc. Rewritable discs like CD-RW and DVD-RW support both data recording and deleting.
When you burn data to the disc, there is still a chance to delete it unless you close the disc during its burning then there’s no way you can delete them. Though rewritable discs support deleting of files, it shouldn’t be done more than twice because it damages the disc itself. In my experience, after burning and deleting files couple of times, my disc became unusable.
