What is the memory from 1k to 640k called ?
1.Extended memory
2.normal memory
3.low memory
4.conventional memory
A binary semaphore -
1.has the value one or zero
2.is essential to binary computers
3.is used only for synchronization
4.is used only for mutual exclusion
A file is
1.an abstraction data type
2.logical storage unit
3.file is usually non volatile
4.All of the above
A page fault occurs
1.when page is not in the memory
2.when the page is in the memory
3.when the page is in blocked state
4.when process is in new state
A process said to be in ______ state if it was waiting for an event that will never occur
1.safe
2.unsafe
3.starvation
4.deadlock
A processor needs software interrupts to
1.test the interrupt system of the processor
2.implement coroutine
3.obtain system services which need execution of privileged instruction
4.return from subroutine
A program at time of execution is called ?
1.dynamic program
2.static program
3.binded program
4.a process
A thread is a ?
1.Heavy weight process
2.multi process
3.inter-thread process
4.light weight process
Access time is the highest in case of
1.floopy disk
2.cache
3.swapping device
4.magnetic disk
Disadvantage of single level directory is -
1.the confusion of file names between different user
2.the confusion of file data
3.Both of the above
4.None of the above
How many page faults occur for optimal page replacement following reference string, with four page frames ? 1,2,3,4,5,3,4,1,6,7,8,7,8,9,7,8,9,5,4,5,4,2
1.14
2.13
3.11
4.12
How many page faults occur in LRU replacement following reference string, with four page frames ? 7,0,1,2,0,3,0,4,2,3,0,3,2,1,2,0,1
1.8
2.7
3.6
4.9
If the disk head located initially at 32, find the no of disk moves required with FCFS if the disk queue of I/O block requests are 98,37,14,124,65,67
1.310
2.324
3.315
4.343
If you dont know which version of MS-DOS you are working with, which command will you use after booting your operating system ?
1.format command
2.FAT command
3.VER command
4.DISK command
In which of the following page replacement policies Belady anomaly may occur ?
1.FIFO
2.Optimal
3.LRU
4.MRO
Magnetic tape can serve as
1.input media
2.output media
3.Secondary storage media
4.All of the above
Memory protection is of no use in
1.single user system
2.non-multiprogramming system
3.non-multitasking system
4.None of the above
PCB is stands for -
1.program control block
2.process control block
3.process communication block
4.None of the above
Process state is a part of
1.process control block
2.inode
3.file allocation table
4.None of the above
Solution of name collision problem is
1.single level directory
2.two level directory
3.tree structure directory
4.None of the above
Supervisor state is
1.entered by program when they enter the processor
2.required to perform any I/O
3.only allowed to the operating system
4.never used
System calla are usually invoked by using
1.a software interrupt
2.polling
3.an indirect jump
4.a privileged instruction
The banker algorithms is used
1.to prevent deadlock in operating systems
2.to detect deadlock in operating systems
3.to rectify a deadlock state
4.None of the above
The essential contents in each entry of a page table is -
1.Virtual page number
2.Page frame number
3.both virtual and page frame
4.access right information
The first fit best fit and worst fit algorithm can be used for-
1.contiguous memory allocation
2.linked allocation of memory
3.index allocation of memory
4.All of the above
The hardware mechanism that enable a device to notify the CPU is called
1.polling
2.interrupt
3.system call
4.None of the above
The lowest level of I/O control consists of -
1.device drivers
2.interrupt handles
3.Both of the above
4.None of the above
The major problem with priority scheduling is ?
1.definite blocking
2.starvation
3.low priority
4.None of the above
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
The number of processes completed per unit time is known as
1.output
2.throughput
3.efficiency
4.capacity
The operating system of a computer serve as a software between the user and the
1.hardware
2.peripheral
3.memory
4.screen
The operating systems manages
1.memory
2.processor
3.disk and I/O devices
4.All of the above
The problem of thrashing is effected by scientifically by-
1.program structure
2.program size
3.primary storage size
4.None of the above
The removal of process from active contention of CPU and reintroduce them into memory later is known as
1.interrupt
2.swapping
3.signal
4.thread
The simplest directly structure is -
1.single level directory
2.two level directory
3.tree structure directory
4.None of the above
The state of process after it encounters an I/O instruction is
1.ready
2.blocked / waiting
3.idle
4.running
There are no cycle in which of the directory -
1.general graph directory
2.a cyclic graph directory
3.one level directory
4.two level directory
Virtual memory is commonly implemented by -
1.segmentation
2.fragmentation
3.demand paging
4.page replacement
What is the shell ?
1.It is hardware component
2.It is command interpreter
3.It is a part in compiler
4.It is a tool in CPU scheduling
Which data structure are used for process scheduling ?
1.stack
2.tree
3.queue
4.heap
Which is not the state of the process ?
1.Blocked
2.Ready
3.Running
4.privileged
Which is the state of process ?
1.Blocked
2.Ready
3.Running
4.All of the above
Which of the following does not interrupt a running process
1.A device
2.timer
3.scheduler process
4.power failure
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
Which of the following statement is false?
1.segmentation suffers from external fragmentation
2.paging suffer from internal fragmentation
3.segmented memory can be paged
4.virtual memory is used only in multi user system
Which scheduling policy is most suitable for a time sharing operating systems ?
1.Shortest job first
2.Round robin
3.First come first serve
4.Elevator
which structure prohibits sharing of file and directory
1.single level directory
2.two level directory
3.tree structure directory
4.None of the above
______ OS pays more attention on the meeting of the the time limit
1.distributed
2.network
3.real time
4.online
_______ allocates the largest hole available in the memory
1.Best fit
2.Worst fit
3.First fit
4.None of the above
_______ is a high level abstraction over semaphore
1.shared memory
2.message passing
3.monitor
4.mutual exclusion