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
151
The command `rm` in Linux is used for which file operation?
Answer:
Remove (Delete)
`rm` is the standard command-line utility for deleting files and directories on Unix-like systems. By default, it deletes files permanently without moving them to the Trash.
152
What is the purpose of setting file permissions?
Answer:
To control who can access files and what they can do with them
File permissions are a fundamental aspect of operating system security, ensuring that sensitive data is protected and that users can only perform authorized actions.
153
What is the main purpose of file compression?
Answer:
To reduce the size of a file, saving storage space and making it faster to transmit.
File compression works by finding and eliminating redundant data within a file, thereby reducing its overall size. This is useful for saving disk space and for speeding up the transfer of files over a network or the internet.
154
Which of these is NOT a standard file operation?
Answer:
Compile
Reading, writing, and executing are fundamental file operations and permissions. Compiling, on the other hand, is a process of converting source code into an executable file and is not a basic file operation in the same sense.
155
What is the main security risk of having files or folders with `777` (`rwxrwxrwx`) permissions?
Answer:
Any user on the system can read, modify, and execute them, which is a major security hole
This permission setting gives complete control to everyone, eliminating any access control. A malicious user could replace an important file or script with their own code.
156
Which extension is used for a plain text file with no formatting?
Answer:
.txt
The ".txt" extension is universally recognized for plain text files, which contain only basic text characters without any styling like bold, italics, or fonts.
157
On a case-sensitive file system like the one used by default in Linux, how are "MyFile.txt" and "myfile.txt" treated?
Answer:
As two different files
Case-sensitive file systems distinguish between uppercase and lowercase letters in file names. Therefore, "MyFile.txt" and "myfile.txt" are considered unique and separate files.
158
In a typical file system, can a directory contain another directory?
Answer:
Yes, this is how the hierarchical structure is created.
The ability for directories to contain other directories is a fundamental concept of modern file systems. This nesting of directories allows for the creation of a tree-like, hierarchical structure for organizing data.
159
Which of the following is an example of lossless compression?
Answer:
A type of compression where the original file can be perfectly reconstructed
Lossless compression reduces file size without losing any information. When the file is decompressed, it is an exact, bit-for-bit copy of the original. This is crucial for text files and programs.
160
To permanently delete a file in Windows without sending it to the Recycle Bin, you can select the file and press:
Answer:
Shift + Delete
Holding the Shift key while pressing the Delete key bypasses the Recycle Bin and prompts for immediate permanent deletion of the selected item(s).