Page 65 - ComputerScience_Class_11

5. BCD stands for ………………… .
a. Bit-coded decimal b. Bit composite decimal
c. Binary convert digit d. Binary coded decimal

Answers
1. b 2. d 3. d 4. b 5. d

B. Fill in the blanks.

1. The process of converting into its equivalent numeric code is called ………………… .
2. In BCD each decimal digit is expressed as a group of ………………… bits.
3. A ………………… is a unit that most computers use to represent any character.
4. ISCII stands for ………………… .
5. A total of ………………… scripts is supported by latest version of Unicode.

Answers
1. encoding 2. 4 3. byte 4. Indian Script Code for Information Interchange 5. 159

C. Answer the following questions:
1. What is the need for character encoding?
Ans. Characters are stored inside the computer as numeric codes. A character encoding provides a key to unlock this binary code. It
is a set of mappings between the bytes in the computer and the characters in the character set.
2. Compare ASCII and Unicode.
Ans.
ASCII UNICODE
Range Represents only the English language and some Includes different languages, scripts and symbols
special characters. and supports all recognised global languages.
Bit Structure Originally 7-bit character set. Extended ASCII uses Uses UTF-8, UTF-16 and UTF-32 encoding
8 bits. schemes.
Number of 128 characters in 7-bit version. 256 characters in Supports 159 scripts containing 144697
Characters extended version. characters.
Relationship Industry standard coding scheme used in Extension of ASCII and backward compatible
computers and web. with it.

3. Write the ASCII equivalent of ASCII.
Ans. A = 65
S = 83
C = 67
I = 73
I = 73
So, ASCII = 65 83 67 73 73
Representing in binary 1000001 1010011 1000011 1001001 1001001
4. What is UTF-8?
Ans. It is a multi-byte, variable-width encoding scheme and is the most popular Unicode encoding scheme. It is backward
compatible with ASCII. It uses 1 byte for standard English letters, 2 bytes for additional Latin and middle Eastern characters,
3 bytes for Asian characters and 4 bytes for additional characters. This encoding scheme is compatible with HTML, XML, JSON
and e-mail.
5. Write two advantages and two disadvantages of the ISCII code.
Ans. Advantages of the ISCII code are as follows:
• Most of the Indian languages can be represented by this code.
• The character set is simple and easy to understand.

Encodings 63