Top 5 Simple Common Interview Questions in Operating Systems

1. What are the types of operations that can be executed on Semaphores ?

Wait ()

Signal ()

2. What is thrashing ?

Thrashing is the condition wherein page fault and swapping operation is increased , due to which there is performance degradation.

3. What is a Zombie process ?

Zombie process in OS refers to the process that has completed its execution, but its entry is still present in Process table due to which it’s Process Control Block (PCB) is not cleaned from the memory . It does not lead to consumption of resources but it shows that the resource is still under utilisation by the process .

4 . What is the difference between paging and segmentation ?

Paging is the memory management technique that allows the OS to retrieve processes from secondary storage into main memory .

Segmentation is the memory management technique which divides the process into smaller modules known as segments .

5. What is the thread in OS ?

Thread is a single execution unit in a process .

Each thread consists of Thread ID, program Counter , Stack and set of registers .

Threads are also known as the lightweight process.