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
111
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.
112
What is the main purpose of file permissions in an operating system?
Answer:
To control access and protect files from unauthorized changes or viewing.
File permissions are a key component of system security.
113
Why is it important to be cautious when opening files with an ".exe" extension from an unknown source?
Answer:
They can contain malicious software (viruses, malware) that can harm your computer.
Since ".exe" files are executable programs, they can be used to deliver and run malicious code on a computer. It's crucial to only run executable files from trusted sources.
114
What is a potential risk of permanently deleting files (e.g., by emptying the Recycle Bin)?
Answer:
You might accidentally remove a file that you later realize you need.
Once a file is permanently deleted, it is generally not recoverable through standard operating system tools. This is why it's important to be certain that you no longer need the files before emptying the Recycle Bin or Trash.
115
A file that is marked as "read-only" can be:
Answer:
Opened, but not modified or saved.
The read-only attribute is a specific permission setting that prevents writing to the file.
116
The "cut" and "paste" commands for a file are equivalent to which single operation?
Answer:
Move
"Cutting" a file flags it to be moved, and "pasting" it in a new location completes the move operation by updating its directory entry.
117
In the context of file permissions, what is a "group"?
Answer:
A collection of user accounts that share a common set of permissions.
In many operating systems, users can be organized into groups. This simplifies administration, as permissions can be assigned to a group, and all members of that group will inherit those permissions.
118
Files with a lot of repetitive data (like a text file with many repeated words) will typically:
Answer:
Compress very well
Compression algorithms excel at finding patterns. Repetitive data is a simple pattern that can be stored very efficiently, leading to high compression ratios.
119
Which of the following is a reserved file name in Windows and cannot be used?
Answer:
NUL
Windows reserves certain names for devices, such as CON, PRN, AUX, and NUL. You cannot create a file with these names.
120
If you move a file from one directory to another on the *same* hard drive partition, what does the operating system typically do?
Answer:
It simply updates the file's pointer in the directory structure without moving the actual data
When moving within the same volume, the OS can perform the operation almost instantly by just changing the file's metadata to point to the new directory. The file's data block on the disk doesn't move.