Operating Systems Fundamentals
Core concepts in operating systems including memory management, process synchronization, and system architecture for public sector exams
Questions
What is a supervisor call?
- A call made by supervisor of the system.
- It is a call with control functions.
- They are privileged calls.
- They are non-privileged calls.
- Supervisor calls can be serviced later.
In paged memory system if page size is increased, then internal fragmentation generally ___________ .
- becomes less
- becomes more
- remains constant
- varies irregularly
- increases or decreases
What is a kernel?
- It is a critical part of the operating system.
- It is the software that monitors the operating system.
- It is a set of primitive functions upon which the operating system is built.
- It is a virus.
- It is an application.
At a particular time, value of counting semaphore is 10. It will become 7 after
- 3 v operations
- 3 p operations
- 5 v and 2 p operations
- 13 p operations and 10 v operations
- options 2 and 4 are correct
Mutual exclusion is a problem that occurs between the _______ .
- processes that are disjoint
- processes that share resources
- processes that do not share resources
- processes that require same turnaround time
- processes that have same burst time
Which of the following is/are single user operating system(s)?
- MS DOS
- Unix
- Xenix
- OS 2
- Only 1 and 3
When does a page fault occur?
- If the page is corrupted
- If the page is present in main memory
- If the page is not in the main memory
- If one tries to divide a number by 0
- If the page is present in secondary memory
If a property of locality holds in a program, then which of the following is true?
- Number of page faults will be more.
- Page faults will be less.
- Page faults will remain the same.
- Page faults will vary irregularly.
- Searching for any page will take more time.
Which of the following is/are necessary condition(s) for deadlock?
- Non-preemption
- Circular wait
- Preemption
- Only 1, 2 and 4
- Mutual exclusion
What do you mean by an overlay?
- A specific memory location
- Overloading the system with many files
- A part of operating system
- Single contiguous memory to run large programs
- Storing the files on hard disk
Fence register is used to protect _________.
- Central Processing Unit (CPU)
- Memory
- File
- Database
- None of these
What is a critical region?
- Part of the operating system that no process can access
- Set of instructions that access shared resources
- Portion of the main memory that can be accessed by any process
- Portion of the main memory that cannot be accessed by any process
- A region where complex calculations are done
Which of the following is a real-time system?
- Railway reservation system
- Process control system
- Payroll processing system
- Student information system
- Management information system
Semaphore is used to solve the problem of __________.
- race condition
- process synchronization
- mutual exclusion
- only 2 and 3
- avoiding deadlock
Which of the following suffers from Belady's anomaly?
- Optimal page replacement policy
- Least recently used policy
- First in first out policy
- Shortest job first
- Round robin