Computer Science/IT MCQs
Topic Notes: Computer Science/IT
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
4971
What is the base or "radix" of a number system?
Answer:
The number of unique digits used in the system
The base, or radix, of a positional numeral system is the number of unique digits, including zero, used to represent numbers. For example, the decimal system has a radix of 10.
4972
EBCDIC is another character encoding standard primarily associated with:
Answer:
IBM mainframe systems
EBCDIC (Extended Binary Coded Decimal Interchange Code) is an 8-bit character encoding that was developed by IBM and is still used on its mainframe and midrange computer operating systems.
4973
What is the output of an XNOR gate when both inputs are the same (0,0 or 1,1)?
Answer:
1
The XNOR (Exclusive NOR) gate is an "equality" gate. It outputs a 1 if the inputs are equal and a 0 if they are different. It is the inverse of the XOR gate.
4974
What do file permissions on a *directory* typically control?
Answer:
The ability to view, create, or delete files within that directory.
Directory permissions govern access to the contents of the directory itself.
4975
"Write" permission for a file typically allows a user to:
Answer:
Modify the file's contents.
Write permission grants the ability to add, delete, or change the data within a file.
4976
Why is UTF-8 the dominant encoding for the World Wide Web?
Answer:
Its backward compatibility with ASCII and space efficiency for English text made it a practical choice
Since a lot of the early web infrastructure and content was ASCII-based, UTF-8 provided a smooth upgrade path. It could handle new international characters while still working perfectly with old systems.
4977
Which two gates are considered "universal gates" because any other logic function can be created using only them?
Answer:
NAND and NOR
You can construct AND, OR, and NOT gates (the three basic building blocks) using only NAND gates or only NOR gates, making them universal.
4978
The number (377)₈ is the largest 3-digit octal number. What is its decimal equivalent?
Answer:
255
(3 \* 8²) + (7 \* 8¹) + (7 \* 8⁰) = (3 \* 64) + (7 \* 8) + (7 \* 1) = 192 + 56 + 7 = 255. Note that this is one less than 8³.
4979
What is the decimal equivalent of the octal number (11)₈?
Answer:
9
To convert an octal number to its decimal equivalent, we multiply each digit by the base (8) raised to the power of its position, starting from 0 for the rightmost digit.
For the octal number (11)₈:
- The rightmost '1' is in the 8^0 position.
- The leftmost '1' is in the 8^1 position.
So, the conversion is calculated as:
(1 * 8^1) + (1 * 8^0)
= (1 * 8) + (1 * 1)
= 8 + 1
= 9
Therefore, the decimal equivalent of (11)₈ is 9.
4980
What is the octal equivalent of the hexadecimal number (1F)₁₆?
Answer:
(37)₈
First, convert (1F)₁₆ to binary: 1 = 0001, F = 1111. So, (00011111)₂. Now, regroup into sets of three from the right: (011 111). Convert to octal: 011 = 3, 111 = 7. The result is (37)₈.