Q. Explain about Magnetic Disk?

A disk is circular platter constructed of nonmagnetic material known as substrate, coated with a magnetisable material. This is used for storing huge amount of data. Usually substrate has been an aluminium or aluminium alloy material. Recently glass substrates have been introduced. The glass substrate has some benefits including the following:

• Improvement in uniformity of magnetic film surface to increase disk reliability.
• A significant decrease in overall surface to help reduce read-write errors.
• Ability to support lower fly heights.
• Better stiffness to reduce disk dynamics.
• Greater ability to endure shock and damage.