Multiple Choice Questions and Correct Answers :-
01) What is operating system?
a) collection of programs that manages hardware resources
b) system service provider to the application programs
c) link to interface the hardware and application programs
d) all of the mentioned
Correct Answers :d
02) To access the services of operating system, the interface is provided by the
a) system calls
b) API
c) library
d) assembly instructions
Correct Answers :a
03) Which one of the following is not true?
a) kernel is the program that constitutes the central core of the operating system
b) kernel is the first part of operating system to load into memory during booting
c) kernel is made of various modules which can not be loaded in running operating system
d) kernel remains in the memory during the entire computer session
Correct Answers :c
04) Which one of the following error will be handle by the operating system?
a) power failure
b) lack of paper in printer
c) connection failure in the network
d) all of the mentioned
Correct Answers :d
05) The scheme used in the above question is known as _______ or ________.
a) sector sparing
b) forwarding
c) backwarding
d) sector utilization
Correct Answers : a and b
06) By operating system, the resource management can be done via
a) time division multiplexing
b) space division multiplexing
c) both (a) and (b)
d) none of the mentioned
Correct Answers :c
7. If a process fails, most operating system write the error information to a
a) log file
b) another running process
c) new file
d) none of the mentioned
Correct Answers :a
08) Which facility dynamically adds probes to a running system, both in user processes and in the kernel?
a) DTrace
b) DLocate
c) DMap
d) DAdd
Correct Answers :a
09) Which one of the following is not a real time operating system?
a) VxWorks
b) Windows CE
c) RTLinux
d) Palm OS
Correct Answers :d
10) The OS X has
a) monolithic kernel
b) hybrid kernel
c) microkernel
d) monolithic kernel with modules
Correct Answers :b
11) The systems which allows only one process execution at a time, are called
a) uniprogramming systems
b) uniprocessing systems
c) unitasking systems
d) none of the mentioned
Correct Answers :a
Explanation:Those systems which allows more than one process execution at a time, are called multiprogramming systems. Uniprocessing means only one processor.
12) In operating system, each process has its own
a) address space and global variables
b) open files
c) pending alarms, signals and signal handlers
d) all of the mentioned
Correct Answers :d
13) In Unix, Which system call creates the new process?
a) fork
b) create
c) new
d) none of the mentioned
Correct Answers :a
14) A process can be terminated due to
a) normal exit
b) fatal error
c) killed by another process
d) all of the mentioned
Correct Answers :d
15) What is the ready state of a process?
a) when process is scheduled to run after some execution
b) when process is unable to run until some task has been completed
c) when process is using the CPU
d) none of the mentioned
Correct Answers :a
Explanation:When process is unable to run until some task has been completed,
the process is in blocked state and if process is using the CPU, it is in running state.
16) What is interprocess communication?
a) communication within the process
b) communication between two process
c) communication between two threads of same process
d) none of the mentioned
Correct Answers :b
17) A set of processes is deadlock if
a) each process is blocked and will remain so forever
b) each process is terminated
c) all processes are trying to kill each other
d) none of the mentioned
Correct Answers :a
18) A process stack does not contain
a) function parameters
b) local variables
c) return addresses
d) PID of child process
Correct Answers :d
19) Which system call returns the process identifier of a terminated child?
a) wait
b) exit
c) fork
d) get
Correct Answers :a
20) The address of the next instruction to be executed by the current process is provided by the
a) CPU registers
b) program counter
c) process stack
d) pipe
Correct Answers :b
21) A Process Control Block(PCB) does not contain which of the following :
a) Code
b) Stack
c) Heap
d) Data
e) Program Counter
f) Process State
g) I/O status information
h) bootstrap program
Correct Answers : h
22) The number of processes completed per unit time is known as __________.
a) Output
b) Throughput
c) Efficiency
d) Capacity
Correct Answers : b
23) The state of a process is defined by :
a) the final activity of the process
b) the activity just executed by the process
c) the activity to next be executed by the process
d) the current activity of the process
Correct Answers : d
24) Which of the following is not the state of a process ?
a) New
b) Old
c) Waiting
d) Running
e) Ready
f) Terminated
Correct Answers : b
25) The Process Control Block is :
a) Process type variable
b) Data Structure
c) a secondary storage section
d) a Block in memory
Correct Answers : b
26) The entry of all the PCBs of the current processes is in :
a) Process Register
b) Program Counter
c) Process Table
d) Process Unit
Correct Answers : c
27) The degree of multi-programming is :
a) the number of processes executed per unit time
b) the number of processes in the ready queue
c) the number of processes in the I/O queue
d) the number of processes in memory
Correct Answers : d
28) A single thread of control allows the process to perform :
a) only one task at a time
b) multiple tasks at a time
c) All of these
Correct Answers : a
29) The objective of multi-programming is to : (choose two)
a) Have some process running at all times
b) Have multiple programs waiting in a queue ready to run
c) To minimize CPU utilization
d) To maximize CPU utilization
Correct Answers : a and d
30) Which of the following do not belong to queues for processes ?
a) Job Queue
b) PCB queue
c) Device Queue
d) Ready Queue
Correct Answers : b
31) When the process issues an I/O request :
a) It is placed in an I/O queue
b) It is placed in a waiting queue
c) It is placed in the ready queue
d) It is placed in the Job queue
Correct Answers : a
32) When a process terminates : (Choose Two)
a) It is removed from all queues
b) It is removed from all, but the job queue
c) Its process control block is de-allocated
d) Its process control block is never de-allocated
Correct Answers : a and c
33) What is a long-term scheduler ?
a) It selects which process has to be brought into the ready queue
b) It selects which process has to be executed next and allocates CPU
c) It selects which process to remove from memory by swapping
d) None of these
Correct Answers : a
34) If all processes I/O bound, the ready queue will almost always be ______, and the Short term Scheduler will have a ______ to do.
a) full,little
b) full,lot
c) empty,little
d) empty,lot
Correct Answers : c
35) What is a medium-term scheduler ?
a) It selects which process has to be brought into the ready queue
b) It selects which process has to be executed next and allocates CPU
c) It selects which process to remove from memory by swapping
d) None of these
Correct Answers : c
36) What is a short-term scheduler ?
a) It selects which process has to be brought into the ready queue
b) It selects which process has to be executed next and allocates CPU
c) It selects which process to remove from memory by swapping
d) None of these
Correct Answers : b
37) The primary distinction between the short term scheduler and the long term scheduler is :
a) The length of their queues
b) The type of processes they schedule
c) The frequency of their execution
d) None of these
Correct Answers : c
38) The only state transition that is initiated by the user process itself is :
a) block
b) wakeup
c) dispatch
d) None of these
Correct Answers : a
39) In a time-sharing operating system, when the time slot given to a process is completed, the process goes from the running state to the :
a) Blocked state
b) Ready state
c) Suspended state
d) Terminated state
Correct Answers : b
40) In a multi-programming environment :
a) the processor executes more than one process at a time
b) the programs are developed by more than one person
c) more than one process resides in the memory
d) a single user can execute many programs at the same time
Correct Answers : c
41) Suppose that a process is in “Blocked” state waiting for some I/O service. When the service is completed, it goes to the :
a) Running state
b) Ready state
c) Suspended state
d) Terminated state
Correct Answers : b
42) An unrecoverable error is known as _________.
a) hard error
b) tough error
c) soft error
d) None of these
Correct Answers : a
43) Which of the following need not necessarily be saved on a context switch between processes ? (GATE CS 2000)
a) General purpose registers
b) Translation look-aside buffer
c) Program counter
d) All of these
Correct Answers : b
44) Which of the following does not interrupt a running process ? (GATE CS 2001)
a) A device
b) Timer
c) Scheduler process
d) Power failure
Correct Answers : c
45) Several processes access and manipulate the same data concurrently and the outcome of the execution depends on the particular order in which
the access takes place, is called a(n) ____.
a) Shared Memory Segments
b) Entry Section
c) Race condition
d) Process Synchronization
Correct Answers : c
46) Which of the following state transitions is not possible ?
a) blocked to running
b) ready to running
c) blocked to ready
d) running to blocked
Correct Answers : a
47) Which module gives control of the CPU to the process selected by the short-term scheduler?
a) dispatcher
b) interrupt
c) scheduler
d) none of the mentioned
Correct Answers :a
48) The processes that are residing in main memory and are ready and waiting to execute are kept on a list called
a) job queue
b) ready queue
c) execution queue
d) process queue
Correct Answers :b
49) The interval from the time of submission of a process to the time of completion is termed as
a) waiting time
b) turnaround time
c) response time
d) throughput
Correct Answers :b
50) Which scheduling algorithm allocates the CPU first to the process that requests the CPU first?
a) first-come, first-served scheduling
b) shortest job scheduling
c) priority scheduling
d) none of the mentioned
Correct Answers :a
51) In priority scheduling algorithm
a) CPU is allocated to the process with highest priority
b) CPU is allocated to the process with lowest priority
c) equal priority processes can not be scheduled
d) none of the mentioned
Correct Answers :a
52) In priority scheduling algorithm, when a process arrives at the ready queue, its priority is compared with the priority of
a) all process
b) currently running process
c) parent process
d) init process
Correct Answers :b
53) Time quantum is defined in
a) shortest job scheduling algorithm
b) round robin scheduling algorithm
c) priority scheduling algorithm
d) multilevel queue scheduling algorithm
Correct Answers :b
54) Process are classified into different groups in
a) shortest job scheduling algorithm
b) round robin scheduling algorithm
c) priority scheduling algorithm
d) multilevel queue scheduling algorithm
Correct Answers :d
55) In multilevel feedback scheduling algorithm
a) a process can move to a different classified ready queue
b) classification of ready queue is permanent
c) processes are not classified into groups
d) none of the mentioned
Correct Answers :a
56) Which one of the following can not be scheduled by the kernel?
a) kernel level thread
b) user level thread
c) process
d) none of the mentioned
Correct Answers :b
Explanation:User level threads are managed by thread library and the kernel in unaware of them.
57) What is the reusable resource?
a) that can be used by one process at a time and is not depleted by that use
b) that can be used by more than one process at a time
c) that can be shared between various threads
d) none of the mentioned
Correct Answers :a
58) Which of the following condition is required for deadlock to be possible?
a) mutual exclusion
b) a process may hold allocated resources while awaiting assignment of other resources
c) no resource can be forcibly removed from a process holding it
d) all of the mentioned
Correct Answers :d
59) A system is in the safe state if
a) the system can allocate resources to each process in some order and still avoid a deadlock
b) there exist a safe sequence
c) both (a) and (b)
d) none of the mentioned
Correct Answers :c
60) The circular wait condition can be prevented by
a) defining a linear ordering of resource types
b) using thread
c) using pipes
d) all of the mentioned
Correct Answers :a
61) Which one of the following is the deadlock avoidance algorithm?
a) banker’s algorithm
b) round-robin algorithm
c) elevator algorithm
d) karn’s algorithm
Correct Answers :a
62) What is the drawback of banker’s algorithm?
a) in advance processes rarely know that how much resource they will need
b) the number of processes changes as time progresses
c) resource once available can disappear
d) all of the mentioned
Correct Answers :d
63) For effective operating system, when to check for deadlock?
a) every time a resource request is made
b) at fixed time intervals
c) both (a) and (b)
d) none of the mentioned
Correct Answers :c
64) A problem encountered in multitasking when a process is perpetually denied necessary resources is called
a) deadlock
b) starvation
c) inversion
d) aging
Correct Answers :b
65) Which one of the following is a visual ( mathematical ) way to determine the deadlock occurrence?
a) resource allocation graph
b) starvation graph
c) inversion graph
d) none of the mentioned
Correct Answers :a
66) To avoid deadlock
a) there must be a fixed number of resources to allocate
b) resource allocation must be done only once
c) all deadlocked processes must be aborted
d) inversion technique can be used
Correct Answers :a
67) CPU fetches the instruction from memory according to the value of
a) program counter
b) status register
c) instruction register
d) program status word
Correct Answers :a
68) A memory buffer used to accommodate a speed differential is called
a) stack pointer
b) cache
c) accumulator
d) disk buffer
Correct Answers :b
69) Which one of the following is the address generated by CPU?
a) physical address
b) absolute address
c) logical address
d) none of the mentioned
Correct Answers :c
70) Run time mapping from virtual to physical address is done by
a) memory management unit
b) CPU
c) PCI
d) none of the mentioned
Correct Answers :a
71) Memory management technique in which system stores and retrieves data from secondary storage for use in main memory is called
a) fragmentation
b) paging
c) mapping
d) none of the mentioned
Correct Answers :b
72) The address of a page table in memory is pointed by
a) stack pointer
b) page table base register
c) page register
d) program counter
Correct Answers :b
73) Program always deals with
a) logical address
b) absolute address
c) physical address
d) relative address
Correct Answers :a
74) The page table contains
a) base address of each page in physical memory
b) page offset
c) page size
d) none of the mentioned
Correct Answers :a
75) What is compaction?
a) a technique for overcoming internal fragmentation
b) a paging technique
c) a technique for overcoming external fragmentation
d) a technique for overcoming fatal error
Correct Answers :c
76) Operating System maintains the page table for
a) each process
b) each thread
c) each instruction
d) each address
Correct Answers :a
77) In segmentation, each address is specified by :
a) a segment number
b) an offset
c) a value
d) a key
Correct Answers : a and b
78) In paging the user provides only ________, which is partitioned by the hardware into ________ and ______.
a) one address, page number, offset
b) one offset, page number, address
c) page number, offset, address
d) None of these
Correct Answers : a
79) Each entry in a segment table has a :
a) segment base
b) segment peak
c) segment limit
d) segment value
Correct Answers : a and c
80) The segment base contains the :
a) starting logical address of the process
b) starting physical address of the segment in memory
c) segment length
d) None of these
Correct Answers : b
81) The segment limit contains the :
a) starting logical address of the process
b) starting physical address of the segment in memory
c) segment length
d) None of these
Correct Answers : c
82) The offset ‘d’ of the logical address must be :
a) greater than segment limit
b) between 0 and segment limit
c) between 0 and the segment number
d) greater than the segment number
Correct Answers : b
83) If the offset is legal :
a) it is used as a physical memory address itself
b) it is subtracted from the segment base to produce the physical memory address
c) it is added to the segment base to produce the physical memory address
d) None of these
Correct Answers : a
84) When the entries in the segment tables of two different processes point to the same physical location :
a) the segments are invalid
b) the processes get blocked
c) segments are shared
d) All of these
Correct Answers : c
85) The protection bit is 0/1 based on : (choose all that apply)
a) write only
b) read only
c) read – write
d) None of these
Correct Answers : b and c
86) If there are 32 segments, each of size 1Kb, then the logical address should have :
a) 13 bits
b) 14 bits
c) 15 bits
d) 16 bits
Correct Answers : a
Explanation: To specify a particular segment, 5 bits are required. To select a particular byte after selecting a page,
10 more bits are required. Hence 15 bits are required.
87) Consider a computer with 8 Mbytes of main memory and a 128 K cache. The cache block size is 4 K.
It uses a direct mapping scheme for cache management. How many different main memory blocks can map onto a given physical cache block ?
a) 2048
b) 256
c) 64
d) 8
Correct Answers : c
88) A multilevel page table is preferred in comparison to a single level page table for translating virtual address to physical address because :
a) it reduces the memory access time to read or write a memory location
b) it helps to reduce the size of page table needed to implement the virtual address space of a process
c) it is required by the translation look aside buffer
d) it helps to reduce the number of page faults in page replacement algorithms
Correct Answers : b
89) The three general methods for delivering content from a server to a client across a network are :
a) unicasting
b) duplex-casting
c) broadcasting
d) multicasting
Correct Answers : a, c, d
90) Unicasting delivers the content to :
a) a single client
b) all clients, regardless whether they want the content or not
c) a group of receivers who indicate they wish to receive the content
d) None of these
Correct Answers : a
91) Broadcasting delivers the content to :
a) a single client
b) all clients, regardless whether they want the content or not
c) a group of receivers who indicate they wish to receive the content
d) None of these
Correct Answers : b
92) Multicasting delivers the content to :
a) a single client
b) all clients, regardless whether they want the content or not
c) a group of receivers who indicate they wish to receive the content
d) None of these
Correct Answers : c
93) RTSP stands for :
a) Real Time Streaming Policy
b) Real Time Streaming Protocol
c) Real Time Systems Protocol
d) Read Time Streaming Policy
Correct Answers : b
94) HTTP is __________. (choose two)
a) a stateful protocol
b) a stateless protocol
c) a protocol that maintains the status of its connection with the client
d) a protocol that does not maintain the status of its connection with the client
Correct Answers : b and d
95) RTSP includes the following states :
a) SETUP
b) PLAY
c) PAUSE
d) STOP
e) TEARDOWN
f) REPLAY
g) All of these
Correct Answers : a, b, c and e
96) In the SETUP state :
a) the server is setup
b) the client is setup
c) the server allocates resources for the client session
d) the client sends requests to the server
Correct Answers : c
97) In the TEARDOWN state :
a) the server breaks down the connection and releases the resources allocated for the session
b) the client breaks down the connection and releases the resources allocated for the session
c) the system crashes
d) None of these
Correct Answers : a
98) RTP stands for :
a) real time protocol
b) real time transmission control protocol
c) real time transmission protocol
d) real time transport protocol
Correct Answers : d
99) The problem with unicast delivery is that the :
a) memory allocation is difficult
b) server must establish a seperate unicast session for each client
c) the routers must support unicasting
d) the clients must be close to the server
Correct Answers : b
100) The difficulty with multicasting from a practical point of view is : (choose all that apply)
a) memory allocation is difficult
b) server must establish a seperate unicast session for each client
c) the routers must support multicasting
d) the clients must be close to the server
Correct Answers : c and d
101) To let a client have random access to a media stream :
a) the protocol used must not be stateless
b) the server must support download
c) the stream should give access rights to the client
d) All of these
Correct Answers : a
102) The model in which one kernel thread is mapped to many user-level threads is called :
a) Many to One model
b) One to Many model
c) Many to Many model
d) One to One model
Correct Answers : a
103) The model in which one user-level thread is mapped to many kernel level threads is called :
a) Many to One model
b) One to Many model
c) Many to Many model
d) One to One model
Correct Answers : b
104) In the Many to One model, if a thread makes a blocking system call :
a) the entire process will be blocked
b) a part of the process will stay blocked, with the rest running
c) the entire process will run
d) None of these
Correct Answers : a
105) In the Many to One model, multiple threads are unable to run in parallel on multiprocessors because :
a) only one thread can access the kernel at a time
b) many user threads have access to just one kernel thread
c) there is only one kernel thread
d) None of these
Correct Answers : a
106) The One to One model allows :
a) increased concurrency
b) decreased concurrency
c) increased or decreased concurrency
d) concurrency equivalent to other models
Correct Answers : a
107) In the One to One model when a thread makes a blocking system call :
a) other threads are strictly prohibited from running
b) other threads are allowed to run
c) other threads only from other processes are allowed to run
d) None of these
Correct Answers : b
108) Which of the following is the drawback of the One to One Model ?
a) increased concurrency provided by this model
b) decreased concurrency provided by this model
c) creating so many threads at once can crash the system
d) creating a user thread requires creating the corresponding kernel thread
Correct Answers : d
109) When is the Many to One model at an advantage ?
a) When the program does not need multi-threading
b) When the program has to be multi-threaded
c) When there is a single processor
d) None of these
Correct Answers : a
110) In the Many to Many model true concurrency cannot be gained because :
a) the kernel can schedule only one thread at a time
b) there are too many threads to handle
c) it is hard to map threads with each other
d) None of these
Correct Answers : a
111) In the Many to Many model when a thread performs a blocking system call :
a) other threads are strictly prohibited from running
b) other threads are allowed to run
c) other threads only from other processes are allowed to run
d) None of these
Correct Answers : b
112) The process of dividing a disk into sectors that the disk controller can read and write,
before a disk can store data is known as : (choose all that apply)
a) partitioning
b) swap space creation
c) low-level formatting
d) physical formatting
Correct Answers : c and d
113) The data structue for a sector typically contains : (choose all that apply)
a) header
b) data area
c) trailer
d) main section
Correct Answers : a, b and c
114) The header and trailer of a sector contain information used by the disk controller such as _________ and _________.
a) main section
b) error correcting codes (ECC)
c) sector number
d) disk identifier
Correct Answers : b and c
115) The two steps the operating system takes to use a disk to hold its files are _______ and ________.
a) partitioning
b) swap space creation
c) caching
d) logical formatting
Correct Answers : a and d
116) The _______ program initializes all aspects of the system, from CPU registers to device controllers and the contents of main memory,
and then starts the operating system.
a) main
b) bootloader
c) bootstrap
d) ROM
Correct Answers : c
117) For most computers, the bootstrap is stored in ____.
a) RAM
b) ROM
c) cache
d) tertiary storage
Correct Answers : b
118) A disk that has a boot partition is called a _________. (choose all that apply)
a) start disk
b) system disk
c) boot disk
d) All of these
Correct Answers : b and c
119) Defective sectors on disks are often known as __________.
a) good blocks
b) destroyed blocks
c) bad blocks
d) None of these
Correct Answers : c
120) In SCSI disks used in high end PCs, the controller maintains a list of _________ on the disk.
The disk is initialized during ________ formatting which sets aside spare sectors not visible to the operating system.
a) destroyed blocks, high level formatting
b) bad blocks, partitioning
c) bad blocks, low level formatting
d) destroyed blocks, partitioning
Correct Answers : c