Page 16 - Modular_v4.0
P. 16

Chapter Profile
                  Secondary Memory

                  This memory is permanent in nature and is not directly accessed by the CPU. It allows users

                  to store data that may be easily retrieved. It is cheaper as compared to primary memory.

                  Secondary memory devices are also called secondary storage devices. They are divided in
                  three categories: Magnetic Disks, Optical Discs and Flash Drives.


                  Magnetic Disk
                  A device such as a hard disk is covered with a magnetic coating. You can record and erase
                  data on a magnetic disk any number of times.

                      Hard Disk: It consists of one or more magnetic disks called platters.
                     It is permanently fixed in the CPU box. It comes in a variety of sizes
                     with storage capacities as high as 5 TB (TeraByte) or even more.
                      External hard disks are also available. They are the hard disks
                     that can be connected to any computer with the help of a USB
                     port.                                                                             Hard disk

                  Optical Disc

                  An optical disc is an electronic data storage medium that can be written onto and read

                  using a low powered laser beam.
                                                         Compact Disc  (CD):  The CD drive reads information
                                                         stored on a compact disc (CD). CD is an external storage

                                                         device. It can hold up to 700 MB of data. A CD is read or
                                                         written on by a CD drive which is fitted in the CPU box.                           Exercise

                        CD               DVD             The types of CDs are CD-ROM, CD-RW and CD-R.
                       Digital Versatile or Video Disc (DVD): DVDs are widely used to store data. A DVD is                                  A.  Tick ( ) the correct option.

                     similar to a CD. It has a storage capacity of 4.7 GB.
                                                                                                                                                 1.  Which of the following is an example of primary memory?
                  Flash Drive                                                                                                                        a.  Hard Disk                                  b.  CD

                  The Flash Drive is a small portable data storage device integrated with a USB (Universal                                           c.  RAM                                        d.  Pen Drive
                  Serial Bus) connector.
                                                                                                                                                 2.  What type of memory holds data even after the computer is switched off?
                      Pen Drive: Pen drive is a storage device which can store a large amount of data. It is
                     connected to a computer using a USB port. It can be carried in your pocket easily. Pen                                          a.  RAM                                        b.  ROM
                     drive has storage capacity of up to 1 TB.                                                                                       c.  Flash Drive                                d.  None of these

                      Memory Card: It is commonly known as multimedia                                                                            3.  A group of 4 bits is known as                   .
                     memory card. It is very small in size usually 1–1.5                                                                             a.  Byte                                       b.  Nibble
                     inches. These are used in mobile phones and digital
                     cameras. You  need  to  have  card reader to  read               Pen drive         Memory card                                  c.  Kilobyte                                   d.  Megabyte

                     stored data on memory card. It has a storage capacity up to 2 TB.




                14   Modular (Ver. 4.0)-III
   11   12   13   14   15   16   17   18   19   20   21