1.
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Which of the following statement about operating systems is correct?
I. Operating system is not the interface between user and computer.
II.
The batch systems used in the second generation of operating systems
allow several user jobs to be in the primary memory of a computer system
at any given time.
III. An interactive operate system provides on-line communication between the user and the system.
IV. In a real-time operating system response time is not a key issue.
(a) Only (I) above (b) (I), (III) and (IV) above
(c) Both (II) and (III) above (d) Both (I) and (III) above
(e) (I), (II), and (IV) above.
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Which of the following statement(s) about operating system is/are correct?
I. It manages the computer’s resources.
II. Some operating systems distinguish between upper case and lower case letters in naming files.
III. MS-Office is an operating system.
IV. The operating system can be viewed as a virtual machine, which runs on top of the computer hardware.
(a) Only (I) above (b) Only (II) above (c) Only (III) above
(d) Only (IV) above (e) (I), (II) and (IV) above.
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In the Unix file system:
(a) Directories and ordinary files are arranged in a hierarchical tree structure
(b) Files can be accessed only by using its absolute path name
(c) A file cannot have many extensions
(d) A directory entry cannot contain a pointer to the file’s inode
(e) ./usr/passwd and /usr/passwd represent two different files.
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Suppose
we have a logical address space of 64 pages of 1024 words each, mapped
onto a physical memory of 256 frames. How many bits are there in the
logical address?
(a) 15 (b) 16 (c) 17 (d) 18 (e) 19.
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Which of the following is not a necessary condition for deadlock to occur?
(a)
Mutual
exclusion
(b) Hold and wait (c) Wait and signal
(d) Circular wait (e) Hold.
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Suppose a system has six equivalent tape drives. Three concurrent processes P1,
P2
and P3 require three, two and four of these tape drives, respectively,
to complete their execution. At a given instance two, one and one of
these tape drives are allocated to these processes P1, P2 and P3
respectively. Which of the following allocations will bring the system
to an unsafe state?
(a) Allocating one tape drive to process P1
(b) Allocating one tape drive to process P2
(c) Allocating one tape drive to process P3
(d) allocating two tape drives to process P3
(e) Allocating one tape drive to P1 and another one to P3.
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A system suffering from an excessive number of page faults is said to be
(a) Crashing (b) Hashing (c) Trashing (d) Thrashing (e) Bashing.
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A
process P consists of five pages P1, P2, P3, P4, and P5, but the
operating system allows it only THREE page-frames. During its lifetime
the process references its pages in the order P1, P2, P3, P2, P1, P4,
P1, P5. If the memory management policy is LFU (Least Frequently Used,
with FIFO used to decide ties), which page will be replaced to make room
for P5?
(a) P1 (b) P2 (c) P3 (d) P4 (e) P5.
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The critical section problem can be solved in numerous ways. What statement is not true?
(a) A test-and-set-lock (TSL) approach is known as a 'busy-wait' solution
(b) A 'busy-wait' solution is good for short duration critical sections
(c) When a binary semaphore is used and when SLEEP() is called the calling process goes into 'ready-to -run' mode
(d) Monitors are more secure than less problematic than semaphores
(e) All tools used to implement CS solutions must have atomic operations.
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A
light weight process (LWP) is supported by a single kernel space
thread, and it in turn supports several user space threads, belonging to
a single user task. Which statement is true?
(I) The user task is made to be multithreaded in order to make it more efficient.
(II) Only kernel space threads can utilize multiple CPU’s power.
(III) If a user space thread blocks due to an I/O operation, the whole user task blocks.
(IV) Kernel space threads have higher context switching overhead than user space threads.
(a) (I), (II) and (IV) are only true (b) (I), (II) and (III) are only true
(c) None is true (d) All are true
(e) (I) and (IV) are only true.
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11.
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Three
non-preemptive jobs J1, J2, J3 are waiting to be run. Their expected
processor times are 6, 3 and 5 time units respectively. In which order
should they be run to minimize the average response time?
(a) J1, J2, J3 (b) J1, J3, J2 (c) J2, J3, J1 (d) J2, J1, J3 (e) J3, J2, J1.
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The
arrival times of four pre-emptive processes P1, P2, P3 and P4 to the
‘ready to run’ queue and their expected PROCESSOR times are given in the
following table.
If
these processes are scheduled by using the pre-emptive
Shortest-Job-First scheduling algorithm, what would be the possible
sequence/sequences of their execution?
(a) P1, P2, P3, P4 (b) P1, P2, P4, P1, P3
(c) P1, P2, P3, P4, P3 (d) P1, P2, P1, P3, P4
(e) P1, P3, P2, P4, P3.
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If /usr/etc/sunos/utils/emacs and utils/emacs denote the same file, what is the current directory?
(a) / (b) sunos (c) /usr/etc (d) emacs (e) //.
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Let
the waiting time of a process for the CPU be the total time the process
waiting in the ready to run queue. Three pre-emptive processes P1, P2,
P3 are in the ready to run queue at time 0. P1 is at the head of the
queue and P3 is at the tail. The expected CPU time for these processes
P1, P2, P3 are 24, 3 and 3 time units respectively. If the PROCESSOR
time quantum given for a process to use the CPU continuously is 4 time
units, what is the average waiting time for a process if the processes
are scheduled using the Round-Robin scheduling algorithm?
(a) 2 time units (b) 9 time units (c) 5.66 time units
(d) 8.66 time units (e) 3.66 time units.
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Consider
a swapping system in which memory consists of the following hole sizes
10K, 4K, 16K, 2K, 11Kbytes. Which holes are taken for the successive
segment requests of 12K, 10K and 9K if the best fit algorithm
(a) 14K, 16K, 11K (b) 14K, 10K, 11K (c) 16K, 14K, 11K
(d) 16K, 11K, 14K (e) 10K,14K,16K.
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What is not the major objective of operating systems?
(a) To act as a resource manager for multiple tasks running on the CPU, the memory and disk resources
(b) To provide a programming interface to the user
(c) To act as an uniform abstract machine on top of a variety of different hardware platforms
(d) To act as a File server to client machines requiring such service
(e) To enable loading and execution of binary code with minimum intervention by the user.
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Which of the following statements comparing the context of a thread with that of a process is true?
(a)
Two processes will share any context; two threads of a same process
will only share the data and the code (text) areas of the context
(b)
Two processes will not share any context; two threads of a same process
will share the data, code (text) and the stack areas of the context
(c)
Two processes will share the data and the code (text) areas of the user
context; two threads of a same process will only share the register
context
(d) The overhead involved in context switching for processor is much higher than that for threads
(e) The overhead involved in context switching for threads is much higher than that for processes.
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A
certain task is multithreaded in such a way that it is supported by two
kernel threads where each kernel thread is supporting more than one
user thread. Which of the following statement is not true about this scenario?
(a) The task can utilize the combined power of more than one CPU, if CPUs are available
(b)
If a user thread makes a blocking system call, the corresponding kernel
thread blocks but the task is still able to continue through the
remaining kernel thread
(c) The task could have been programmed using a thread library such as POSIX threads or Java threads
(d) If a user thread makes a blocking system call, the corresponding kernel thread blocks and the task will also be blocked
(e) Kernel threads capability needs to be built into the operating system, and cannot be provided by a system call library.
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One needs a good practical example of a “producer-consumer” type problem from among the following.
(I)
A multithreaded audio server, where a thread writes digitized sound
into a circular buffer and another thread reads it over to a web page.
(II) a printer spooler where files are spooled on to the printer queue, to be taken and printed by the printer driver.
(III) a shared data base updated by simultaneous queries.
Which of the following is/are true of such a good practical example?
(a) Only (I) is true (b) Only (II) is true (c) Both (I) and (III) are true
(d) Both (I) and (II) above (e) All are true.
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Demand paging and swapping are two widely used memory management techniques. Which of the following statements is not true in this regard?
(a) Moving the whole user context of a process between the main memory and the virtual memory is known as swapping
(b)
Moving pages corresponding to the user context of a process between the
main memory and the virtual memory as and when required is known as
demand paging
(c) Demand paging incurs a higher overhead than swapping
(d)
If both demand paging and swapping are implemented by the memory
management system, the default mechanism resorted to is demand paging
(e)
When the system’s main memory space becomes comparatively smaller than
the space required to run its applications, swapping activity becomes
more visible.
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21.
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Which of the following can be said about a segmentation fault caused when a process is active?
(a) It will recover from the fault transparently to the user, by moving the required page from the secondary memory
(b) The fault’s cause may most likely be an error in programming
(c) It will not abruptly terminate the process and a core image of the process will be saved for further observations
(d) It will cause the process to go into the ‘blocked’ state
(e) It will most likely be caused by a hardware fault.
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A common programming construct for implementing mutual exclusion which uses condition variables is called
(a) Semaphore (b) Deadlock (c) Monitor
(d) Locking interrupts (e) Threads.
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Suppose
requests have recently arrived for data on cylinders 25, 46, 12, and 3,
in that order, and that the read-write head is currently at cylinder
20. If the disk scheduling policy is SSTF, the outstanding requests
will be serviced in the order
(a) 25, 46, 12, 3 (b) 25, 46, 3, 12 (c) 3, 12, 25, 46
(d) 25, 12, 3, 46 (e) 12,3,25,46.
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DMA stands for
(a) Direct Management access (b) Direct memory access
(c) Dual memory access (d) Data memory access
(e) Dual memory array.
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Which of the following disk-scheduling methods is most likely to lead to starvation for requests on inner or outer cylinders?
(a) FCFS (b) SSTF (c) SCAN (d) C-SCAN (e) b-SCAN.
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Which of the following is in correct order of size, smallest first?
(a) Cylinder, track, sector (b) Cylinder, sector, track
(c) Sector, track, cylinder (d) Sector, cylinder, track
(e) Track, cylinder, sector.
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A process that executes a READ instruction for a data record currently on disk will undergo a process state transition from
(a) Ready to blocked (b) Running to blocked (c) Blocked to ready
(d) Blocked to running (e) Terminated.
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In
a certain system, process A has just arrived at time 0, process B at
time 3, and process C at time 6. A needs 5 seconds in the CPU, B 3
seconds, and C 1 second. All processes are totally CPU-bound and
process-switching time is negligible, so that after 9 seconds all
processes have completed. At what time does process B complete if the
process-scheduling algorithm is preemptive SJF and the quantum is 1
second?
(a) 6 (b) 7 (c) 8 (d) 9 (e) 10.
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If the value of a binary semaphore S is 0, and a process executes a WAIT instruction on S, then
(a) S will remain zero and the process will proceed
(b) S will remain zero and the process will be placed on a queue
(c) S will become one and the process will proceed
(d) S will become one and the process will be placed on a queue
(e) S will become -1 and the process will not be placed on a queue.
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The
process of collecting fragments of available memory space into
contiguous blocks by moving programs and data in a computer's memory or
disk is known as
(a) Compaction (b) Coalescing (c) Segmentation (d) Fragmentation (e) Paging.
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Which
of the following controls all the computer resources and provides the
base upon which the application programs can be written?
(a) Application Software (b) C.P.U (c) Operating System
(d) Bare Hardware (e) Device Drivers.
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Which of the following system call loads a process into memory?
(a) Load (b) Create (c) Fork (d) Execv (e) Copy.
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Expand the term UNICS
(a) Uniplexed Information Computing System
(b) Unipoint Information Computing System
(c) Uniplexed Instruction Computing System
(d) Unipoint Instruction Computing System
(e) Union Instruction Common System.
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Which of the following software layer is used between the kernel and the user computations in the network O.S?
(a) Local O.S (b) Network O.S (c) Global O.S
(d) Distributed O.S (e) Remote O.S.
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Which of the following allows many users to share the computer simultaneously?
(a) Time Sharing O.S (b) Real Time O.S
(c) Interactive O.S (d) Batch O.S (e) Network O.S.
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If a program is under execution by CPU then we say the process is under
(a) CPU Burst (b) Process (c) I/O Burst
(d) Ready Queue (e) New State.
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Each process is represented in the operating system by its own
(a) Thread (b) PCB (c) State (d) Instructions (e) PCC.
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The amount of time that a job waits in a ready queue for getting selected by CPU is called
(a)
Turn around
time (b)
Waiting time (c) Completion time
(d) Submission time (e) Throughput.
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The process of storing and restoring from PCB is called
(a) Loading (b) Relocation (c) Dispatcher
(d) Process (e) context switch.
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Which of the following memory management scheme loads all pages of a program from disk into main memory?
(a) Paging (b) Demand paging
(c) Segmentation (d) Segmentation with paging
(e) Demand segmentation.
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Which of the following page replacement algorithm use the technique of replace that page which is not used in the near future?
(a) LRU (b) LFU (c) ORA (d) FIFO (e) MFU.
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The set of pages that a process is currently using is called as
(a) Program (b) Page Group (c) Working Group
(d) Working Set (e) None of the above.
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Which of the following registers contains starting address of the program in the main memory?
(a) Address register (b) Base register (c) GPR
(d) Index register (e) Limit register.
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The process of converting logical address into physical address is known as
(a) Conversion (b) Displacement (c) Relocation
(d) Transfer (e) None of the above.
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In a segmentation scheme the logical memory will be divided into
(a) Pages (b) Frames (c) Blocks (d) Cells (e) Segments.
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Which of the following area is used to store the O.S programs in the main memory?
(a) User memory area (b) Monitor memory area
(c) Heap area (d) Stack area (e) Data area.
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In Unix which of the following system calls returns the meta data about a file?
(a) fstat (b) mstat (c) Metacall (d) Sigabort (e) fork.
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Information in the file is processed in order, one record after another. This mode of access is called________.
(a) Relative (b) Sequential (c) Direct (d) Index (e) Indexed-sequential.
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Which of the technique is used to recover the process from starvation situation?
(a) Paging (b) Aging (c) Compaction (d) Starvation (e) Reduction.
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Before
we store data into a disk it must be divided into sectors and from
where the disk controller can read and write. This is known as________.
(a) Low-level formatting (b) Fragmenting (c) High-level formatting
(d) Cleaning (e) Portioning a disk.
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The
disk controller can be told to replace each bad sector logically with
one of the spare sectors in the disk. This scheme is known as_______.
(a) Sector sparing (b) Sector slipping (c) Forwarding
(d) Back word replacing (e) Sector replace.
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Controlling the access of programs, processes or users to the resources defined by the system is known as_______.
(a) Prevention (b) Security (c) Protection
(d) Access stop (e) Access right.
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Which of the following symbol is used to represent the process vertex in a RAG?
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Which of the following mechanism is used to achieve concurrency control?
(a) Clusters (b) Triggers (c) Control access
(d) Cursors (e) Locks.
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Every process before starting execution should know what resources are allocated to it. This is known as
(a) Know-to-need (b) Need-to-Know (c) Know about what
(d) Need-to-use (e) Know-to-use.
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The ability to execute an operation on an object is known as
(a) Access Right (b) Access Control (c) Domain Knowledge
(d) Control Right (e) Protection.
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The time required to move the disk head to the desired track is known as
(a) Access Time (b) Track Time (c) Latency Time
(d) Seek Time (e) Block Time.
| |
A distributed system is a collection of processors that do not share_______.
(a) CPU (b) Memory (c) I/O devices (d) Network (e) File.
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The name of the file does not reveal any hint of the file’s physical storage location is called_____.
(a) Location independence (b) Protection (c) Location transparency
(d) File migration (e) Inter-machine interface.
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software
entity running on one or more machines and providing a particular type
of function to a priori unknown clients is called________.
(a) Client (b) Server (c) Service (d) Process (e) None of the above.
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Answers
1.
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Answer : (c)
Reason: Remaining all are contradictory statements.
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Answer : (e)
Reason: MS-Office is a package.
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Answer : (a)
Reason:
A file can have many extensions; A directory can contain a pointer to
the files inode Files can not be accessed only by using its absolute
path name.
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Answer : (b)
Reason: Remaining all are contradictory.
| |
Answer : (c)
Reason: Wait and signal is not a necessary condition for deadlock to occur.
| |
Answer : (d)
Reason: Allocating two tape drives to process P3 will Put the system in safe remaining drive the system to be unsafe.
| |
Answer : (d)
Reason: Remaining all are not related to page faults in Operating system.
| |
Answer : (d)
Reason: D is the right choice for the above situation.
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Answer : (c)
Reason: By remaining all statements we can solve critical section problem.
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Answer : (a)
Reason: iii is a contradictory statement.
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11.
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Answer : (c)
Reason: If the above order is not followed the response time would be more.
|
Answer : (b)
Reason: If the order of the jobs is in P1, P2, P4, P1, P3 the average turnaround time would be smaller.
| |
Answer : (b)
Reason: It is the right choice as other are not satisfying hierarchical structure of file system.
| |
Answer : (c)
Reason: Average waiting time is 5.66 time units so C is the right choice.
| |
Answer : (b)
Reason: According to the best fit strategy 14K,10K,11K holes are taken.
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Answer : (d)
Reason: The remaining all are the objectives of OS but not the choice D.
| |
Answer : (d)
Reason: Remaining all are contradictory.
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Answer : (d)
Reason: D is the right choice according to the scenarios of threads.
| |
Answer : (d)
Reason: A shared Database updated by simultaneous queries is not a good producer and consumer problem.
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Answer : (c)
Reason: Demand paging doesnot incur high overhead than swapping.
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21.
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Answer : (b)
Reason: It will abruptly terminate the process and a core image of the process will be saved for further observations.
|
Answer : (c)
Reason: Monitor uses a condition variable for implementing mutual exclusion.
| |
Answer : (d)
Reason: Remaining all donot satisfy the SSTF policy.
| |
Answer : (b)
Reason: DMA stands for direct memory Acess.
| |
Answer : (b)
Reason: SSTF disk scheduling method is most likely to lead to starvation for requests on inner or outer cylinders.
| |
Answer : (c)
Reason: Sector track and cylinder is the correct order of size.
| |
Answer : (b)
Reason: Running to blocked is the correct process state transition.
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Answer : (d)
Reason: In Preemptive SJF the process B complete in 9 seconds.
| |
Answer : (b)
Reason: According to the condition of semaphore s will remain zero and the process will be placed on a quesue.
| |
Answer : (a)
Reason: Compaction is the process of collecting fragments of available memory space into contiguous blocks by moving programs and data in a computer's memory or disk.
|
Answer : (c)
Reason
: Operating system controls all the computer resources and provides the
base upon which the application programs can be written
| |
Answer : (a)
Reason : Load system call loads a process into main memory
| |
Answer : (a)
Reason : Uniplexed Information Computing System
| |
Answer : (b)
Reason : Network Operating System is the software layer used between the kernel and the user
| |
Answer : (a)
Reason : Timesharing Operating System allows many users to share the computer simultaneously
| |
Answer : (a)
Reason : CPU burst
| |
Answer : (b)
Reason : Each process is represented in the operating system by its own PCB
| |
Answer : (b)
Reason: The amount of time that a job waits in a ready queue for getting selected by CPU is called Waiting time.
| |
Answer : (e)
Reason : The process of storing and restoring from PCB is called Context switch
| |
Answer : (a)
Reason: Paging memory management scheme loads all pages of a program from disk into main memory.
|
Answer : (c)
Reason: ORA page replacement algorithm uses the technique of replace that page which is not used in the near future.
| |
Answer : (d)
Reason: The set of pages that a process is currently using is called Working set.
| |
Answer : (b)
Reason : Base register contains starting address of the program in the main memory
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Answer : (c)
Reason: The process of converting logical address into physical address is called relocation.
| |
Answer : (e)
Reason: In a segmentation scheme the logical memory will be divided into Segments.
| |
Answer : (b)
Reason: The place where OS programs are stored in the main memory is called Monitor memory area.
| |
Answer : (a)
Reason : fstat system cal returns the met data about a file
| |
Answer : (b)
Reason : Sequential orer
| |
Answer : (b)
Reason : Aging technique is used to recover the process from starvation
| |
Answer : (d)
Reason : Low-level formatting or Physical formatting
|
Answer : (a)
Reason
: The disk controller can be told to replace each bad sector logically
with one of the spare sectors in the disk is called Sector sparing
| |
Answer : (c)
Reason: Controlling the access of programs, processes or users to the resources defined by the system is known as protection.
| |
Answer : (b)
Reason :
| |
Answer : (e)
Reason : Locks mechanism is used to achieve concurrency control
| |
Answer : (b)
Reason : Every process before starting execution should know what resources are allocated to it is known as Nee-to-know
| |
Answer : (a)
Reason : The ability to execute an operation on an object is known as Access Right
| |
Answer : (d)
Reason : The time required to move the disk head to the desired track is known as Seek Time
| |
Answer : (b)
Reason: A distributed system is a collection of processors that do not share Memory.
| |
Answer : (c)
Reason
: The name of the file does not reveal any hint of the Low-level
formatting or Physical formatting h file’s physical storage location is
called Location Transparency
| |
Answer : (c)
Reason
: Software entity running on one or more machines and providing a
particular type of function to a point to a priori unknown clients is
called Service
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