Showing posts with label Operating System. Show all posts
Showing posts with label Operating System. Show all posts

Operating System MCQ Questions

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1) Which is the best process to access number of records from the same file ?
  1. A batch job
  2. An on-line job
  3. A real time job
  4. All of above
Show/Hide Answer
Answer = A 
Explanation: Many batch jobs are run in parallel and JCL is used to control the operation of each job
2) What is the name of the arrangement where several central processing units share one memory ?
  1. Multi tasking
  2. Multi programming
  3. Multi processing
  4. Concurrent programming
Show/Hide Answer
Answer =  C 
Explanation: Multiprogramming is the allocation of a computer system and its resources to more than one concurrent application, job or user
3) Banker's algorithm for resource allocation deals with ?
  1. Dead lock prevention
  2. Dead lock avoidance
  3. Dead lock recovery
  4. Mutual Exclusion
Show/Hide Answer
Answer = B 
Explanation: The Banker's algorithm is a resource allocation and deadlock avoidance algorithm developed by Edsger Dijkstra that tests for safety by simulating the allocation of predetermined maximum possible amounts of all resources, and then makes a "s-state" check to test for possible deadlock conditions for all other pending activities, before deciding whether allocation should be allowed to continue.
4) If the CPU scheduling policy is STF, the average waiting time (without prevention) will be ?
  1. 12.8 ms
  2. 6.8 ms
  3. 17 ms
  4. None of above
Show/Hide Answer
Answer = B 
Explanation: No Explanation
5) Producer consumer problem can be solved using ?
  1. Semaphores
  2. Event counters
  3. Monitors
  4. All of above
Show/Hide Answer
Answer = D 
Explanation: No Explanation
6) If the CPU scheduling policy is priority scheduling without pre-emption, the average waiting time will be ?
  1. 19 ms
  2. 11.8 ms
  3. 10.8 ms
  4. None of above
Show/Hide Answer
Answer =  C 
Explanation: No Explanation
7) Situation where two or more processes are reading or writing some shared data and the final result depends upon who runs precisely is called ?
  1. Race Condition
  2. Critical Section
  3. Mutual Exclusion
  4. Message Passing
Show/Hide Answer
Answer = A 
Explanation: A race condition or race hazard is a type of flaw in an electronic or software system where the output is dependent on the sequence or timing of other uncontrollable events.
8) In partitioned memory allocation scheme ?
  1. The best fit algorithm is always better than the first fit algorithm
  2. The best fir algorithm is always better that best fit algorithm
  3. The superiority of the first fir algorithm depends upon the sequence of memory request
  4. None of above
Show/Hide Answer
Answer =  C 
Explanation: No Explanation
9) The main function of dispatcher is ?
  1. swapping a process to the disk
  2. Assigning reads process to the CPU
  3. Suspending some of the processes when the CPU load is high
  4. Bring processes from the disk to the main memory
Show/Hide Answer
Answer = B 
Explanation:  The dispatcher is the module that gives control of the CPU to the process selected by the short-time scheduler
10) For implementing multiprogramming system ?
  1. special support from
  2. special support from processor is not essential
  3. cache memory must be available
  4. mote than one processor must be available
Show/Hide Answer
Answer = B 
Explanation: No Explanation
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Operating System Multiple Choice Questions - Set 5

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Operating system multiple choice questions and answers with appropriate explanation.

1)  PMTLR is acronym for ?
  1. Page Map Table Limit Register
  2. Page Memory Table With Limit Register
  3. Both A and B
  4. None of these
Show/Hide Answer
Answer =  A 
Explanation: N/A

2) Paging is ?
  1. Virtual memory
  2. Memory management scheme
  3. Allocation of memory
  4. Deadlock prevention scheme
Show/Hide Answer
Answer =  B
Explanation: paging is one of the memory-management schemes by which a computer can store and retrieve data from secondary storage for use in main memory.

3) Chaining and indexing are the strategies of ?
  1. Contiguous allocation
  2. Non - Contiguous allocation
  3. Partition allocation
  4. Static allocation
Show/Hide Answer
Answer = B 
Explanation: Chaining and Indexing are Non Contiguous Allocation strategies that contains pointes to the memory locations.
 

4) Which of the following scheduler is in charge of handling the swapped out process ?
  1. short term
  2. long term
  3. medium term
  4. none of these
Show/Hide Answer
Answer =  A
Explanation: The short-term scheduler (also known as the CPU scheduler) decides which of the ready, in-memory processes are to be executed (allocated a CPU) next following a clock interrupt, an IO interrupt, an operating system call or another form of signal.

5) Round robin scheduling algorithm falls under the category of ?
  1. Preemptive scheduling
  2. Non preemptive scheduling
  3. sometimes preemptive sometimes non preemptive
  4. None of these
Show/Hide Answer
Answer =  A
Explanation: Round-robin (RR) is one of the simplest scheduling algorithms for processes in an operating system. As the term is generally used, time slices are assigned to each process in equal portions and in circular order, handling all processes without priority.In order to schedule processes fairly, a round-robin scheduler generally employs time-sharing, giving each job a time slot or quantum (its allowance of CPU time), and interrupting the job if it is not completed by then. So it falls under preemptive scheduling.

6) Only the process executing the critical section is allowed access to the shared variable, all other processes should prevented from doing so until the completion of the critical section. This is often referred to as ?
  1. Mutual exclusion
  2. Semaphores
  3. Deadlock
  4. Interprocess communication
Show/Hide Answer
Answer =  A
Explanation: N/A
7) Partition Description Table (PDT) collect the ?
  1. Current Partition Status
  2. Attributes
  3. Both A and B
  4. None of these
Show/Hide Answer
Answer =  C
Explanation: n/a

8) Belady's Anomaly is a behavior of which page replacement algorithm ?
  1. FIFO
  2. Optimal
  3. Circular FIFO
  4. LRU
Show/Hide Answer
Answer = A 
Explanation: Bélády's anomaly proves that it is possible to have more page faults when increasing the number of page frames while using the First in First Out (FIFO) page replacement algorithm.

9) Which of the following is an operating system call ?
  1. CREATE
  2. LINK
  3. SYSTEM
  4. All of these
Show/Hide Answer
Answer = D 
Explanation: N/A

10) The reference bit is used for the purpose of ?
  1. Improving MRU algorithm
  2. Implementing LRU page replacement algorithm
  3. Checking of the page table entry is in cache memory
  4. Checking to see if parameters are passed to a procedure by value or by address
Show/Hide Answer
Answer = A
Explanation: N/A
Tags : Operating system objective type questions with answers, Operating system MCQs, OS mcq, OS quiz
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Multiple Choice Questions On Operating System - Set 4

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Following are the Multiple choice questions related to the Operating System with the case study of UNIX concepts.
 

1) In UNIX the status of the process may be ?
  1. running
  2. orphan
  3. sleeping
  4. zombie
  5. All of above
Show/Hide Answer
Answer = E 
Explanation:No Explanation

2) Which of the following processes has a PID I ?
  1. Kernel
  2. UNIX
  3. hilt
  4. shell
Show/Hide Answer
Answer = C 
Explanation:No Explanation

3) The PID of kernel process is ?
  1. undefined
  2. 0
  3. 1
  4. 3
Show/Hide Answer
Answer = B
Explanation: No Explanation 
4) Which of the following command is not a cursor movement command ?
  1. n
  2. a
  3. $
  4. j
  5. None of above
Show/Hide Answer
Answer = B 
Explanation:No  Explanation 
5) The Commands used to compare the files is known as ?

  1. comp
  2. du
  3. cmp
  4. ccp
  5. None
Show/Hide Answer
Answer = C 
Explanation: No Explanation
6) Which of the following command is used with vi editor to delete a single character ?
  1. z
  2. y
  3. a
  4. x
  5. None of above
Show/Hide Answer
Answer = D 
Explanation: No Explanation
7) Which command is used with vi editor to move the cursor one row up ?
  1. i
  2. j
  3. h
  4. k
  5. None  of above
Show/Hide Answer
Answer = D 
Explanation: No Explanation 
8) Which command is used with the vi editor to move the cursor to the left ?
  1. i
  2. k
  3. j
  4. h
  5. None of above
Show/Hide Answer
Answer = D 
Explanation: No Explanation 
9) Which command is used with the vi editor to save file and remain in the editing mode ?
  1. :q
  2. q!
  3. :w
  4. :x
  5. None of above
Show/Hide Answer
Answer = C 
Explanation: No Explanation 
10) Which command is used to extract specific columns from the file ?
  1. cat
  2. grep
  3. cut
  4. paste
  5. None of above
Show/Hide Answer
Answer = C 
Explanation: No Explanation

Tags : Operating system multiple choice questions with answers, Operating system MCQs, Objective type questions on Operating system with answers, Objective type questions on Operating system, Quiz questions on operating system, Operating system MCQ, Multiple choice questions On Operating system, UGC-NET test preperation, Computer subjects quiz
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Multiple Choice Questions On Operating System With Answers - Set 3

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1)Virtual memory is ?
  1. Extremely large main memory
  2. Extremely large secondary memory
  3. An illusion of an extremely large memory
  4. A type of memory used in super computers
Show/Hide Answer
Answer = C
Explanation:  Virtual memory is a feature of Operating System that enables a process to use a memory independent of other processes.
2) Spatial locality refers to the problem that once a location  is referenced  ?
  1. It will not be referenced again
  2. It will be referenced again
  3. A nearby location will be referenced soon
  4. None of Above
Show/Hide Answer
Answer =  B
Explanation: Spatial locality or locality of reference stats that the same value or related value is going to be referenced again.
3)  Which of the following is an example of SPOOLED device?
  1. The terminal used to enter the input data for a program being executed
  2. The secondary memory device in a virtual memory system
  3. A line printer used to print the output of number of job's
  4. None of above
Show/Hide Answer
Answer = C 
Explanation:Line printer used to print the output of number of job's is an example of print spooling. In print spooling documents are loaded into the buffer and then the printer pulls then off the buffer at its own rate.

4) Page fault occurs when ?
  1. The page in corrupted by application software
  2. The page is in main memory
  3. The page is not in main memory
  4. One tries to divide number by 0
Show/Hide Answer
Answer = C
Explanation:Page fault occurs when the page that is not in the main memory is tried to be accessed.

5)  Overlays is ?
  1. A part of Operating System
  2. A specific memory location
  3. A single contiguous memory that was used in the olden days for running large programs by swapping
  4. Overloading the system with many user files
Show/Hide Answer
Answer = C
 Explanation: An overlay is when a process replaces itself with the code of another program.


6) Determine the number of page faults when references to pages occurs in the order 1,2,4,5,2,1,2,4. Assume that the main memory can accommodate 3 pages and the main memory already has the pages 1 and 2. With page 1 having been brought earlier that page 2(Assume LRU algorithm is used) ?
  1. 3
  2. 5
  3. 4
  4. None
Show/Hide Answer
Answer = C 
Explanation:As the reference string is 1,2,4,5,2,1,2,4 so if LRU page replacement algorithm is used then there will be 4 page faults.

7) Concurrent processed are processed that ?
  1. Do not overlap in time
  2. Overlap in time
  3. Are executed by processor at the same time
  4. None of Above
Show/Hide Answer
Answer = B 
Explanation:Concurrent means something that executed at the same time ad something else.

8) The rage replacement policy that sometimes leads to more page faults when the size of the memory is increased is ?
  1. FIFO
  2. LRU
  3. no such policy exists
  4. None of Above
Show/Hide Answer
Answer = A 
Explanation:If the size of memory is increased and FIFO page replacement algorithm is used then there will be more page faults.

9) The only transition that is initiated by the user process itself is ?
  1. block
  2. dispatch
  3. wake up
  4. None of Above
Show/Hide Answer
Answer = A
10) Working set(r,k) at an instance of time t, is a set of ?
  1. k future references that operating system will make
  2. Future references that the operating system will make in the next 'k' time units
  3. k references with high frequency
  4. Pages that have been referenced in the last k time units
Show/Hide Answer
Answer = D
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Multiple Choice Questions On Operating System - Page 2

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1) 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
Show/Hide Answer
Answer = D
Explanation:  BAK extension is used for the backup files however the extension should be removed before opening the file to open it correctly. Eg :  "myfile.doc.bak"should be renamed with "myfile.doc".
2) FIFO scheduling is.....
  1. Preemptive Scheduling
  2. Non Preemptive Scheduling
  3. Deadline Scheduling
  4. Fair share scheduling
Show/Hide Answer
Answer = B
Explanation: In the non preemptive scheduling the CPU can not take back from the process to which it is assigned, until it completes its execution
3)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
Show/Hide Answer
Answer = B
Explanation: The old state of the process can be saved through the concept of context switching.
4)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
Show/Hide Answer
Answer = A
Explanation: In an operating system, a deadlock is a situation which occurs when a process enters a waiting state because a resource requested by it is being held by another waiting process, which in turn is waiting for another resource. If a process is unable to change its state indefinitely because the resources requested by it are being used by other waiting process, then the system is said to be in a deadlock.
5)A thread
  1. is a lightweight process where the context switching is low
  2. is a lightweight process where the context switching is high
  3. is used to speed up paging
  4. none of the above
Show/Hide Answer
Answer = A
6) A tree structured file directory system
  1. allows easy storage and retrieval of file names
  2. is a much debated unnecessary feature
  3. is not essential when we have millions of files
  4. none of the above
Show/Hide Answer
Answer = A
Explanation: It is easy to access anything if it is in hierarchical structure.
7) Full Form Of PCB
  1. Program Control Block
  2. Process Control Block
  3. Process Communication Block
  4. None of the above
Show/Hide Answer
Answer = B
Explanation: It is also called the Task Controlling Block or Task Struct that contains the information needed to manage a particular process
8)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
Show/Hide Answer
Answer = C
Explanation: Under the concept of demand paging , the page is brought into the memory only when it is needed
9) 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
Show/Hide Answer
Answer = D
Explanation: Through Multiprogramming multiple processes gets executed at a same time
10) 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
Show/Hide Answer
Answer = C


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Multiple Choice Questions On Operating System - Page 1

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1) Round Robin algorithm is essentially the preemptive version of ?
  1. FIFO
  2. Shortest Job First
  3. Shortest Remaining
  4. Longest time first
Show/Hide Answer
Answer = a 
Explanation: In round robin algorithm time slices are assigned to the processes in equal portion and in circular order.
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
Show/Hide Answer
Answer = a
Explanation: A page fault occurs when a process accesses a page that has been mapped into the address space, but is not loaded into the physical memory. 
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
Show/Hide Answer
Answer = D
Explanation: The choice of the software should be compatible with the hardware and should not be expensive enough.
4) 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. 
Show/Hide Answer
Answer = B 
Explanation:  A Shell is the command line interpreter that provides the traditional user interface for the UNIX operating system. Users direct the operation of the computer by entering commands as text for a command line interpreter to execute or by creating text scripts of one or more such commands.
5)  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
Show/Hide Answer
Answer = C 
Explanation: Dynamic linking provides the facility to load or unload routines at runtime

6)  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
Show/Hide Answer
Answer = A 
Explanation:   All the processes that are waiting for the completion of some event such as I/O operation or a signal are in Blocked state.
7) What is the memory from 1K - 640K called ?
  1. Extended Memory
  2. Normal Memory
  3. Low Memory
  4. Conventional Memory
Show/Hide Answer
Answer = D 

8) 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.
Show/Hide Answer
Answer = C 
Explanation: Virtual memory allows a program to be designed as though there is only one kind of memory, "virtual" memory, which behaves like directly addressable read/write memory (RAM).
9) Which is not the state of the process ?
  1. Blocked
  2. Running
  3. Ready
  4. Privileged 
Show/Hide Answer
Answer = D
10) The number of processes completed per unit time is known as.... ?
  1. Output
  2. Throughput
  3. Efficiency
  4. Capacity
Show/Hide Answer
Answer = B 
Explanation: Throughput is the amount of data transfer from one place to another. It is measured in Kbps, Gbps, Mbps
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