Coding Text

Question 1

What does each memory circuit in a computer represent?

Answer 1

Each memory circuit can be ON or OFF, represented as 1 or 0.

Question 2

How many combinations are possible with:
(i) 2 bits (ii) 3 bits (iii) 4 bits (iv) 8 bits?

Answer 2

2 bits: 4

3 bits: 8

4 bits: 16

8 bits: 256

Question 3

How many characters can ASCII represent with 7 bits?

Answer 3

128 characters.

Question 4

What is the ASCII code in binary and decimal for the character ‘0’?

Answer 4

Binary: 00110000
Decimal: 48.

Question 5

What is the purpose of a parity bit?

Answer 5

It is used for error detection by ensuring a correct number of 1s in a byte.

Question 6

What are the rules for even parity?

Answer 6

Add a parity bit:

If odd number of 1s → Parity bit = 1

If even number of 1s → Parity bit = 0

Question 7

How does the majority voting method detect and correct errors?

Answer 7

Each bit is transmitted three times, and the most common value in the triplet is used.

Question 8

What is the role of a check digit in error detection?

Answer 8

It is calculated from other digits in the code to identify human errors during data entry.

Question 9

What are two advantages of Unicode compared to ASCII?

Answer 9

1. Represents a larger set of characters, including various languages.
2. Standardized globally for better data compatibility.

Question 10

Name a disadvantage of Unicode compared to ASCII.

Answer 10

Unicode uses more memory as it has a larger range.

Question 11

What is the binary for character ‘A’ in ASCII?

Answer 11

Binary: 01000001
Decimal: 65.

Question 12

What will the parity bit be for ‘P’ (ASCII: 01010000) with even parity?

Answer 12

: 1 (making it 101010000).

Question 13

What is a single binary digit called?

Answer 13

A bit (Binary Digit).

Question 14

How many bits are in a byte, and what does a byte represent?

Answer 14

byte has 8 bits and typically represents one character in memory.

Question 15

What is the decimal value of the ASCII code for the letter ‘B’ and how is it represented in 7-bit binary?

Answer 15

Decimal: 66
Binary: 1000010.

Question 16

What is the pattern for numeric characters in ASCII, starting from ‘0’?

Answer 16

Numeric ‘0’ starts at 48, with each subsequent digit incrementing by 1.
E.g., ‘1’ = 49, ‘2’ = 50, etc.

Question 17

What is the difference between ASCII codes for uppercase and lowercase letters?

Answer 17

Lowercase letters are 32 more than their corresponding uppercase letters.
Example: ‘A’ = 65, ‘a’ = 97.

Question 18

What is a primary advantage of the ASCII system?

Answer 18

It is compact, using only 7 bits to represent 128 characters.

Question 19

What is a limitation of ASCII compared to Unicode?

Answer 19

ASCII cannot represent characters beyond the basic English alphabet, numbers, and symbols.

Question 20

What is the difference between even and odd parity?

Answer 20

Even parity ensures the total number of 1s is even.

Odd parity ensures the total number of 1s is odd.

Question 21

In a transmitted bit sequence 010, what correction is made by majority voting?

Answer 21

The sequence is corrected to 000, assuming the error occurred in one bit.

Question 22

How is the check digit calculated in a weighted number system?

Answer 22

Multiply each digit by its weight, sum the results, divide by 11, subtract the remainder from 11.

Question 23

What is Unicode, and how does it differ from ASCII?

Answer 23

Unicode is a character encoding standard capable of representing characters from all languages, while ASCII is limited to 128 or 256 characters.

Question 24

How does parity bit error detection differ from majority voting?

Answer 24

Parity detects single-bit errors but cannot correct them, while majority voting can both detect and correct errors.

Question 25

Calculate the parity bit for the sequence 1001010 using even parity.

Answer 25

Parity bit = 1; the sequence becomes 11001010.

Question 26

What is the binary for the ASCII character ‘&’?

Answer 26

00100110

Question 27

How many characters can Unicode represent compared to ASCII?

Answer 27

Unicode can represent over 1 million characters, compared to 128 or 256 for ASCII.