Why dont we have CDs of different capacities -like 100Mb CD OR 250Mb CD ?

Question

CDs are generally availbae as 700MB and sometimes the smaller ones 140MB. I was wondering why only these two capacities ?

Answer 1

Manufacturing cost of CD depends on its physical size and not on the capacity in GB. Therefore no one makes CD of smaller capacity.

Answer 2

Because that's the physical size of the disk. Mini-CD or full size. That's it. (there was a 650 MB CD, but that has pretty much disappeared - the 700's are everywhere). You want to get the most you can fit on the CD - which is 700 MB. Or roughly 140 on a mini CD. Some CDs that are cut into odd shapes (like business cards with 2 curved sides and 2 straight sides) can have small sizes, but. At .10-20 cents each, no one I've met so far has ever asked the question, "why can't I get a smaller capacity CD".

Answer 3

the cds dont have that much capcity to hold such enormous data A CD is a fairly simple piece of plastic, about four one-hundredths (4/100) of an inch (1.2 mm) thick. Most of a CD consists of an injection-molded piece of clear polycarbonate plastic. During manufacturing, this plastic is impressed with microscopic bumps arranged as a single, continuous, extremely long spiral track of data. I'll return to the bumps in a moment. Once the clear piece of polycarbonate is formed, a thin, reflective aluminum layer is sputtered onto the disc, covering the bumps. Then a thin acrylic layer is sprayed over the aluminum to protect it. The label is then printed onto the acrylic. CD has a single spiral track of data, circling from the inside of the disc to the outside. The fact that the spiral track starts at the center means that the CD can be smaller than 4.8 inches (12 cm) if desired, and in fact there are now plastic baseball cards and business cards that you can put in a CD player. CD business cards hold about 2 MB of data before the size and shape of the card cuts off the spiral, so to cut it short u would have to squeez the data and that can only be done by improving the type of cds made as the blue ray technologhy u might have heard about it can store more data than dvds

Answer 4

cds with 700mb are can be use ful in many ways where 100 or 250 mb are not so use ful so 700mb cds are available


for u the cds which are rewritable are avilable with them u can use in ur way this cds can be rewritable by deleting the files in it after use these cds are same as a memory card of cell phones it can be rewritable many times