Coding Text Flashcards
What does each memory circuit in a computer represent?
Each memory circuit can be ON or OFF, represented as 1 or 0.
How many combinations are possible with:
(i) 2 bits (ii) 3 bits (iii) 4 bits (iv) 8 bits?
2 bits: 4
3 bits: 8
4 bits: 16
8 bits: 256
How many characters can ASCII represent with 7 bits?
128 characters.
What is the ASCII code in binary and decimal for the character ‘0’?
Binary: 00110000
Decimal: 48.
What is the purpose of a parity bit?
It is used for error detection by ensuring a correct number of 1s in a byte.
What are the rules for even parity?
Add a parity bit:
If odd number of 1s → Parity bit = 1
If even number of 1s → Parity bit = 0
How does the majority voting method detect and correct errors?
Each bit is transmitted three times, and the most common value in the triplet is used.
What is the role of a check digit in error detection?
It is calculated from other digits in the code to identify human errors during data entry.
What are two advantages of Unicode compared to ASCII?
- Represents a larger set of characters, including various languages.
- Standardized globally for better data compatibility.
Name a disadvantage of Unicode compared to ASCII.
Unicode uses more memory as it has a larger range.
What is the binary for character ‘A’ in ASCII?
Binary: 01000001
Decimal: 65.
What will the parity bit be for ‘P’ (ASCII: 01010000) with even parity?
: 1 (making it 101010000).
What is a single binary digit called?
A bit (Binary Digit).
How many bits are in a byte, and what does a byte represent?
byte has 8 bits and typically represents one character in memory.
What is the decimal value of the ASCII code for the letter ‘B’ and how is it represented in 7-bit binary?
Decimal: 66
Binary: 1000010.
What is the pattern for numeric characters in ASCII, starting from ‘0’?
Numeric ‘0’ starts at 48, with each subsequent digit incrementing by 1.
E.g., ‘1’ = 49, ‘2’ = 50, etc.
What is the difference between ASCII codes for uppercase and lowercase letters?
Lowercase letters are 32 more than their corresponding uppercase letters.
Example: ‘A’ = 65, ‘a’ = 97.
What is a primary advantage of the ASCII system?
It is compact, using only 7 bits to represent 128 characters.
What is a limitation of ASCII compared to Unicode?
ASCII cannot represent characters beyond the basic English alphabet, numbers, and symbols.
What is the difference between even and odd parity?
Even parity ensures the total number of 1s is even.
Odd parity ensures the total number of 1s is odd.
In a transmitted bit sequence 010, what correction is made by majority voting?
The sequence is corrected to 000, assuming the error occurred in one bit.
How is the check digit calculated in a weighted number system?
Multiply each digit by its weight, sum the results, divide by 11, subtract the remainder from 11.
What is Unicode, and how does it differ from ASCII?
Unicode is a character encoding standard capable of representing characters from all languages, while ASCII is limited to 128 or 256 characters.
How does parity bit error detection differ from majority voting?
Parity detects single-bit errors but cannot correct them, while majority voting can both detect and correct errors.
