data representation

Question 1

what is data representation

Answer 1

it refers to the form in which date is stored, processed and transferred

Question 2

what is a bit

Answer 2

it is the smallest unit of data in computers, it represents a binary state of 0 and 1

Question 3

why do we need hexadecimal

Answer 3

. computers operate with binary numbers represented with 0 and 1
. can be very long and hard for humans to understand
. hexadecimal is shorter and easier to understand

Question 4

uses of hexadecimal

Answer 4

. color codes in websites
.machine code and assembly language
. mac address

Question 5

what is binary coded decimal

Answer 5

it is a way of representing decimal numbers using binary digits. each decimal number is represented by a group of 4 binary digits

Question 6

uses of bcd

Answer 6

any scenario where a single digit needs to be displayed eh calculator and digital clock

Question 7

describe how danery integers larger than 9 can be converted into bcd

Answer 7

each danery digit would be written as a 4 bit binary number for eg 46 would be 0100 0110

Question 8

describe how a 8 bit bcd can be converted into a danery digit

Answer 8

the binary digits will be split into groups of 4 bits, starting from the right

Question 9

unsigned binary numbers

Answer 9

a way of representing numbers using 1 and 0, there is no concept of positive or negative numbers

Question 10

signed binary numbers

Answer 10

a way of representing numbers using both negative and positive values , 0 means positive and 1 means negative

Question 11

state how an overflow can occur when adding two binary numbers

Answer 11

computers have fixed memory spaces, sometimes after calculation the number of bits end up being more than the amount which can be stored

Question 12

why was ASCII developed

Answer 12

back then different manufacturers used different character codes, this made it difficult for computers of different companies to communicate, ASCII was developed to set the same codes for text characters

Question 13

describe charcteristics of ASCII

Answer 13

A= 65 a= 97
there is 7 bits
128 characters can be represented 0-127
it is standard american code
64 32 16 8 4 2 1

Question 14

charcteristics of extended ASCII

Answer 14

8 bits
256 characters can be represented
128 64 32 16 8 4 2 1
128 to 255

Question 15

what are disadvantages of ASCII codes

Answer 15

only 128 characters can be represented
many characters in other languages cannot be represented
in extended ASCII the characters from 128-255 may be coded differently in different systems

Question 16

how unicode is designed to overcome the disadvantages of ASCII

Answer 16

unicode uses upto 32 bits
it is designed to be a superset if ASCII
it is designed so most characters in other languages can be represented