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
131
What happens if you change a file's extension from ".txt" to ".jpg"?
Answer:
The file's contents remain the same, but the operating system will try to open it with an image viewer.
Changing a file's extension does not change the data inside the file. It only changes how the operating system identifies the file type, which will likely result in an error when trying to open it with the wrong program.
132
What is the result of the binary multiplication (11)₂ \* (10)₂?
Answer:
(110)₂
This is equivalent to multiplying by 2 in decimal, which means shifting the bits to the left and adding a 0. So, 11 becomes 110. (In decimal: 3 \* 2 = 6).
133
Which of these file extensions is commonly associated with an image file format?
Answer:
.png
The ".png" (Portable Network Graphics) extension is a popular raster graphics file format that supports lossless data compression.
134
What are the digits used in the binary number system?
Answer:
0, 1
Binary is a base-2 system, meaning it only has two possible digits: 0 and 1. Each digit is called a "bit".
135
What does the file extension ".xls" traditionally indicate?
Answer:
A Microsoft Excel spreadsheet (older format)
The ".xls" extension was the default format for Microsoft Excel spreadsheets before the introduction of the XML-based ".xlsx" format in Excel 2007.
136
What does "backward compatibility" mean in the context of UTF-8 and ASCII?
Answer:
Any valid ASCII text file is also a valid UTF-8 text file
Because UTF-8 uses the exact same single-byte values for the first 128 characters as ASCII, a file containing only those characters can be interpreted correctly by systems expecting either encoding.
137
Which file operation creates a new, empty file in a specified location?
Answer:
Create
The "create" operation is the fundamental action of generating a new file on the file system.
138
When converting binary to hexadecimal, bits are grouped in sets of:
Answer:
4
Since 2⁴ = 16, each group of four binary digits corresponds to exactly one hexadecimal digit.
139
The octal digit '7' is equivalent to which binary value?
Answer:
111
Each octal digit represents three bits. The octal digit '7' represents the decimal value 7. The 3-bit binary representation of 7 is 111 (4 + 2 + 1).
140
[cite_start]Which of the following has a 16-bit coding scheme? [cite: 485]
Answer:
Unicode
The Unicode standard was originally designed as a 16-bit character encoding system. [cite: 486] [cite_start]This allows it to represent a vast number of characters (up to 65,536), which is necessary to support alphabets and symbols from languages around the world. [cite: 487]