Practice Operating System in CS Thinking
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
System software that manages hardware resources (processor, memory, storage, devices) and provides services for application programs. The operating system acts as the intermediary between the user and the hardware, handling tasks like multitasking, file management, and device communication.
The OS is the manager of your computer — it decides which program gets the processor's attention, handles file storage, and provides the interface you see.
Showing a random 20 of 50 problems.
Example 1
mediumOn a phone, what software manages the touchscreen, battery, and app switching collectively?
Example 2
easyWhy does the OS keep running after you close all your apps?
Example 3
mediumUser mode vs kernel mode: which one is privileged and can directly access hardware?
Example 4
mediumA user plugs a USB camera that the OS doesn't recognize. Walk through what the OS needs to do to make it usable.
Example 5
challengeOn a 4-core CPU running 4 CPU-bound processes, is true parallelism possible? How does the OS scheduler differ from the single-core case?
Example 6
easyThe OS component that decides which process runs next is called the ____.
Example 7
mediumWhen you save a document, the app calls the OS to write to disk. Which component does the OS use to talk to the specific disk?
Example 8
easyWhich of these is application software, not OS: (a) file explorer kernel module, (b) photo editor?
Example 9
hardAn OS uses round-robin with 4 processes and a 10 ms quantum. If process B needs 80 ms of CPU, how long until it finishes (assume no I/O, ignore overhead)?
Example 10
easyThe OS hides device details so apps just 'ask' for services. What is this principle called?
Example 11
mediumA program needs more RAM than is free. The OS moves some data to disk to free memory. Name this OS technique.
Example 12
mediumA file system is the part of the OS that does what?
Example 13
mediumTwo programs both want to write to the same file at once. Which OS role prevents conflict?
Example 14
hardAfter an OS update, an old printer stops working. Why is updating the driver usually the fix, not buying new hardware?
Example 15
hardWhy is using a hardware feature called the MMU essential to enforcing process isolation?
Example 16
easyTrue or false: an operating system manages memory, devices, and files.
Example 17
easyName the OS role that organizes files into folders and tracks where they are stored.
Example 18
hardExplain the concept of user permissions in an operating system. Why does a school network restrict what students can install or access?
Example 19
easyRunning several programs seemingly at once is which OS feature?
Example 20
mediumExplain why you need device drivers and what happens when you plug in a new printer without the correct driver installed.