Objective questions from operating system

1) Round robin scheduling is essentially the preemptive version of ________. 
1 FIFO 
2 Shortest job first 
3 Shortest remaining 
4 Longest time first 
Right Ans ) 1 

2) A page fault occurs 
1 when the page is not in the memory 
2 when the page is in the memory 
3 when the process enters the blocked state 
4 when the process is in the ready state 
Right Ans ) 1

3) Which of the following will determine your choice of systems software for your computer ? 
1 Is the applications software you want to use compatible with it ? 
2 Is it expensive ? 
3 Is it compatible with your hardware ? 
4 Both 1 and 3 
Right Ans ) 4 

4) Let S and Q be two semaphores initialized to 1, where P0 and P1 processes the following statements wait(S);wait(Q); —; signal(S);signal(Q) and wait(Q); wait(S);—;signal(Q);signal(S); respectively. The above situation depicts a _________ . 
1 Semaphore 
2 Deadlock 
3 Signal 
4 Interrupt 
Right Ans ) 2 

5) What is a shell ? 
1 It is a hardware component 
2 It is a command interpreter 
3 It is a part in compiler 
4 It is a tool in CPU scheduling 
Right Ans ) 2 

6) Routine is not loaded until it is called. All routines are kept on disk in a relocatable load format. The main program is loaded into memory & is executed. This type of loading is called _________ 
1 Static loading 
2 Dynamic loading 
3 Dynamic linking 
4 Overlays 
Right Ans ) 3 

7) In the blocked state 
1 the processes waiting for I/O are found 
2 the process which is running is found 
3 the processes waiting for the processor are found 
4 none of the above 
Right Ans ) 1 

8) What is the memory from 1K – 640K called ? 
1 Extended Memory 
2 Normal Memory 
3 Low Memory 
4 Conventional Memory 
Right Ans ) 4 

9) Virtual memory is __________. 
1 An extremely large main memory 
2 An extremely large secondary memory 
3 An illusion of extremely large main memory 
4 A type of memory used in super computers. 
Right Ans ) 3 

10) The process related to process control, file management, device management, information about system and communication that is requested by any higher level language can be performed by __________. 
1 Editors 
2 Compilers 
3 System Call 
4 Caching 
Right Ans ) 3 

11) If the Disk head is located initially at 32, find the number of disk moves required with FCFS if the disk queue of I/O blocks requests are 98,37,14,124,65,67. 
1 310 
2 324 
3 315 
4 321 
Right Ans ) 4 

12) Multiprogramming systems ________. 
1 Are easier to develop than single programming systems 
2 Execute each job faster 
3 Execute more jobs in the same time 
4 Are used only on large main frame computers 
Right Ans ) 3 

13) Which is not the state of the process ? 
1 Blocked 
2 Running 
3 Ready 
4 Privileged 
Right Ans ) 4 

14) The solution to Critical Section Problem is : Mutual Exclusion, Progress and Bounded Waiting. 
1 The statement is false 
2 The statement is true. 
3 The statement is contradictory. 
4 None of the above 
Right Ans ) 2 

15) The problem of thrashing is effected scientifically by ________. 
1 Program structure 
2 Program size 
3 Primary storage size 
4 None of the above 
Right Ans ) 1 

16) The state of a process after it encounters an I/O instruction is __________. 
1 Ready 
2 Blocked/Waiting 
3 Idle 
4 Running 
Right Ans ) 2 

17) The number of processes completed per unit time is known as __________. 
1 Output 
2 Throughput 
3 Efficiency 
4 Capacity 
Right Ans ) 2 

18) _________ is the situation in which a process is waiting on another process,which is also waiting on another process … which is waiting on the first process. None of the processes involved in this circular wait are making progress. 
1 Deadlock 
2 Starvation 
3 Dormant 
4 None of the above 
Right Ans ) 1 

19) Which of the following file name extension suggests that the file is Backup copy of another file ? 
1 TXT 
2 COM 
3 BAS 
4 BAK 
Right Ans ) 4 

20) Which technique was introduced because a single job could not keep both the CPU and the I/O devices busy? 
1 Time-sharing 
2 SPOOLing 
3 Preemptive scheduling 
4 Multiprogramming 
Right Ans ) 4 

21) A critical region 
1 is a piece of code which only one process executes at a time 
2 is a region prone to deadlock 
3 is a piece of code which only a finite number of processes execute 
4 is found only in Windows NT operation system 
Right Ans ) 1 

22) The mechanism that bring a page into memory only when it is needed is called _____________ 
1 Segmentation 
2 Fragmentation 
3 Demand Paging 
4 Page Replacement 
Right Ans ) 3 

23) PCB = 
1 Program Control Block 
2 Process Control Block 
3 Process Communication Block 
4 None of the above 
Right Ans ) 2 

24) FIFO scheduling is ________. 
1 Preemptive Scheduling 
2 Non Preemptive Scheduling 
3 Deadline Scheduling 
4 Fair share scheduling 
Right Ans ) 2 

25) Switching the CPU to another Process requires to save state of the old process and loading new process state is called as __________. 
1 Process Blocking 
2 Context Switch 
3 Time Sharing 
4 None of the above 
Right Ans ) 2 

26) Which directory implementation is used in most Operating System? 
1 Single level directory structure 
2 Two level directory structure 
3 Tree directory structure 
4 Acyclic directory structure 
Right Ans ) 3 

27) The Banker¿s algorithm is used 
1 to prevent deadlock in operating systems 
2 to detect deadlock in operating systems 
3 to rectify a deadlocked state 
4 none of the above 
Right Ans ) 1 

28) A thread 
1 is a lightweight process where the context switching is low 
2 is a lightweight process where the context swithching is high 
3 is used to speed up paging 
4 none of the above 
Right Ans ) 1 

29) ______ is a high level abstraction over Semaphore. 
1 Shared memory 
2 Message passing 
3 Monitor 
4 Mutual exclusion 
Right Ans ) 3 

30) A tree sturctured file directory system 
1 allows easy storage and retrieval of file names 
2 is a much debated unecessary feature 
3 is not essential when we have millions of files 
4 none of the above 
Right Ans ) 1



Second Part

1) Routine is not loaded until it is called. All routines are kept on disk in a relocatable load format. The main program is loaded into memory & is executed. This type of loading is called _________ 
1 Static loading 
2 Dynamic loading 
3 Dynamic linking 
4 Overlays 
Ans ) 3 

2) Which of the following is crucial time while accessing data on the disk? 
1 Seek time 
2 Rotational time 
3 Transmission time 
4 Waiting time 
Ans ) 1 

3) The host repeatedly checks if the controller is busy until it is not. It is in a loop that status register’s busy bit becomes clear. This is called _____________ and a mechanism for the hardware controller to notify the CPU that it is ready is called ___________. 
1 Interrupt and Polling 
2 Polling and Spooling 
3 Polling and Interrupt 
4 Deadlock and Starvation 
Ans ) 3 

4) Unix Operating System is an __________. 
1 Time Sharing Operating System 
2 Multi-User Operating System 
3 Multi-tasking Operating System 
4 All the Above 
Ans ) 4 

5) Which of the following memory allocation scheme suffers from External fragmentation? 
1 Segmentation 
2 Pure demand paging 
3 Swapping 
4 Paging 
Ans ) 1 

6) Information about a process is maintained in a _________. 
1 Stack 
2 Translation Lookaside Buffer 
3 Process Control Block 
4 Program Control Block 
Ans ) 3 

7) Distributed OS works on the ________ principle. 
1 File Foundation 
2 Single system image 
3 Multi system image 
4 Networking image 
Ans ) 2 

8) The problem of fragmentation arises in ________. 
1 Static storage allocation 
2 Stack allocation storage 
3 Stack allocation with dynamic binding 
4 Heap allocation 
Ans ) 4 

9) Which file system does DOS typically use ? 
1 FAT16 
2 FAT32 
3 NTFS 
4 WNFS 
Ans ) 1 

10) The program is known as _________ which interacts with the inner part of called kernel. 
1 Compiler 
2 Device Driver 
3 Protocol 
4 Shell 
Ans ) 4 

11) The time taken by the disk arm to locate the specific address of a sector for getting information is called __________. 
1 Rotational Latency 
2 Seek Time 
3 Search Time 
4 Response Time 
Ans ) 2 

12) Which file system does Windows 95 typically use ? 
1 FAT16 
2 FAT32 
3 NTFS 
4 LMFS 
Ans ) 2 

13) Identify the odd thing in the services of operating system. 
1 Accounting 
2 Protection 
3 Error detection and correction 
4 Dead lock handling 
Ans ) 3 

14) Cryptography technique is used in ________. 
1 Polling 
2 Job Scheduling 
3 Protection 
4 File Management 
Ans ) 3 

15) Which of the following is not advantage of multiprogramming? 
1 Increased throughput 
2 Shorter response time 
3 Decreased operating system overhead 
4 Ability to assign priorities to jobs 
Ans ) 3 

16) In ______ OS, the response time is very critical. 
1 Multitasking 
2 Batch 
3 Online 
4 Real-time 
Ans ) 4 

17) An optimal scheduling algorithm in terms of minimizing the average waiting time of a given set of processes is ________. 
1 FCFS scheduling algorithm 
2 Round robin scheduling algorithm 
3 Shorest job – first scheduling algorithm 
4 None of the above 
Ans ) 3 

18) Real time systems are ________. 
1 Primarily used on mainframe computers 
2 Used for monitoring events as they occur 
3 Used for program development 
4 Used for real time interactive users 
Ans ) 2 

19) Which technique was introduced because a single job could not keep both the CPU and the I/O devices busy? 
1 Time-sharing 
2 SPOOLing 
3 Preemptive scheduling 
4 Multiprogramming 
Ans ) 4 

20) Inter process communication can be done through __________. 
1 Mails 
2 Messages 
3 System calls 
4 Traps 
Ans ) 2 

21) In Priority Scheduling a priority number (integer) is associated with each process. The CPU is allocated to the process with the highest priority (smallest integer = highest priority). The problem of, Starvation ? low priority processes may never execute, is resolved by __________. 
1 Terminating the process. 
2 Aging 
3 Mutual Exclusion 
4 Semaphore 
Ans ) 2 

22) CPU performance is measured through ________. 
1 Throughput 
2 MHz 
3 Flaps 
4 None of the above 
Ans ) 1 

23) PCB = 
1 Program Control Block 
2 Process Control Block 
3 Process Communication Block 
4 None of the above 
Ans ) 2 

24) Software is a program that directs the overall operation of the computer, facilitates its use and interacts with the user. What are the different types of this software ? 
1 Operating system 
2 Language Compiler 
3 Utilities 
4 All of the above 
Ans ) 4 

25) A __________ is a software that manages the time of a microprocessor to ensure that all time critical events are processed as efficiently as possible. This software allows the system activities to be divided into multiple independent elements called tasks. 
1 Kernel 
2 Shell 
3 Processor 
4 Device Driver 
Ans ) 1 

26) The primary job of the operating system of a computer is to ________. 
1 Command Resources 
2 Manage Resources 
3 Provide Utilities 
4 Be user friendly 
Ans ) 2 

27) With the round robin CPU scheduling in a time-shared system ________. 
1 Using very large time slice degenerates in to first come first served algorithm 
2 Using extremely small time slices improve performance 
3 Using extremely small time slices degenerate in to last in first out algorithm 
4 Using medium sized time slices leads to shortest request time first algorithm 
Ans ) 1 

28) Which of the following is a criterion to evaluate a scheduling algorithm? 
1 CPU Utilization: Keep CPU utilization as high as possible. 
2 Throughput: number of processes completed per unit time. 
3 Waiting Time: Amount of time spent ready to run but not running. 
4 All of the above 
Ans ) 4 

29) Which of the following is contained in Process Control Block (PCB)?
1 Process Number 
2 List of Open files 
3 Memory Limits 
4 All of the Above 
Ans ) 4 

30) Super computers typically employ _______. 
1 Real time Operating system 
2 Multiprocessors OS 
3 desktop OS 
4 None of the above 
Ans ) 2