OSG 202 Test version I
QN=42 (7464) Which is the maximum partition size, if the FAT type is FAT-32 and the block size is 4 KB? a. 1 TB b. 128 MB c. 256 MB d. 512 MB
1 TB
QN=29 (7068) A computer with a 32-bit address uses a two-level page table. Virtual addresses are split into a 10-bit top-level page table field, an 12-bit second-level page table field, and an offset. How large are the pages? a. 4-KB page b. 2-KB page c. 1-KB page d. 512B page
1-KB page
QN=25 (7041) Assume the Memory Manager receives a request for a block of 200. When the worst-fit algorithm is used, ____ is the beginning address of the block granted by the Memory Manager. Beginning Address Memory Block Size 4075 105 5225 5 6785 600 7560 20 7600 205 10250 4050 a. 7600 b. 10250 c. 6785 d. 4075
10250
QN=28 (7061) Suppose a virtual address space of 2^32 words and the page size is 2^12 words. If the virtual address is 12345678 in Hexadecimal, what would be the page number in Hexadecimal? a. 123 b. 1234 c. 12345 d. 123456
12345
QN=21 (7011) Five batch jobs A through E, arrive at a computer center at almost the same time. They have estimated running times of 8, 6, 2, 10, and 4 minutes. Their (externally determined) priorities are 3, 5, 2, 1, and 4, respectively, with 5 being the highest priority. Determine the average turnaround time for priority scheduling. Ignore process switching overhead. a. 6 minutes b. 12.8 minutes c. 18.8 minutes d. 16.8 minutes
16.8 minutes
QN=28 (7057) If there are 64 pages and the page size is 2048 words, what is the length of logical address? a. 14 bits b. 15 bits c. 16 bits d. 17 bits
17 bits
QN=46 (7510) Imagine that a certain printer can print 400 characters per second and that the time to write a character to the printer's output register is so short it can be ignored. If to run this printer using interrupt-driven I/O and each character printed requires an interrupt that takes 50 µsec all-in to service. How many percent of the CPU does the interrupt overhead cost? a. 2% of the CPU b. 98% of the CPU c. 4% of the CPU d. 96% of the CPU
2% of the CPU
QN=22 (7015) Assume jobs A-D arrive in quick succession in the READY queue. Using round robin scheduling (quantum=4), the turnaround time for job D is ____. Arrival time: 0 1 2 3 Job: A B C D CPU cycle: 8 4 9 5 a. 7 b. 20 c. 22 d. 24
22
QN=13 (6948) How many percent of the CPU time is wasted, when a computer system has enough room to hold two program and these programs are idle waiting for I/O half the time? a. 50% b. 25% c. 75% d. None of the other choices
25%
QN=14 (6956) How many ways is Thread implemented? a. 1 b. 2 c. 3 d. None of the other choice
3
QN=29 (7065) A system with 32 bit virtual address. If the page size is 4 KB and each table entry occupies 4 bytes, what is the size of the page table? a. 1 MB b. 2 MB c. 4 MB d. 8 MB
4 MB
QN=13 (6951) How many percent is CPU utilization, when a computer system has enough room to hold two program and these programs are idle waiting for I/O half the time? a. 50% b. 25% c. 75%
75%
QN=21 (7007) Five batch jobs A through E, arrive at a computer center at almost the same time. They have estimated running times of 8, 6, 2, 10, and 4 minutes. Determine the average waiting time for SJF (Shortest job first) scheduling. Ignore process switching overhead. a. 14 minutes b. 8 minutes c. 6 minutes d. 18.8 minutes
8 minutes
QN=22 (7017) Assume jobs A-D arrive at almost the same time in the READY queue. Determine the average turnaround time for SJF scheduling. Ignore process switching overhead Job: A B C D CPU cycle: 5 2 6 4 a. 5.5 b. 6.8 c. 9.0 d. 11.1
9.0
QN=30 (7072) Which of the following statements is incorrect about Translation Look-aside Buffer (TLB)? a. A TLB is sometimes known as an associative memory b. Each entry of a TLB contains the information about one page, including the virtual page number and the corresponding page frame c. A TLB miss implies a disk operation will follow d. None of the other choices
A TLB miss implies a disk operation will follow
QN=15 (6963) Critical Region (Section) concept used in interprocess communication is: a. A part of the program where the shared memory is accessed b. A part of shared data c. A part of shared memory d. None of the other choices
A part of the program where the shared memory is accessed
QN=36 (7421) ____ is a specialized WRITE command for existing data files that allows for adding records to end of the file. a. APPEND b. UPDATE c. REWRITE d. MODIFY
APPEND
QN=20 (7002) Some systems increase the priority of jobs that have been in the system for an unusually long time to expedite their exit, which is known as ____.? a. Lagging b. Bumping c. Aging d. Accelerated priority
Aging
QN=10 (6909) A simple structuring model for monolithic system includes: a. A main program that invokes the requested service procedure b. A set of service procedures that carry out the system calls c. A set of utility procedures that help the service procedures d. All of the other choices
All of the other choices
QN=17 (6978) Which of the following is true about Atomic action on semaphores? a. Checking the value b. Changing the value c. Possibly going to sleep d. All of the other choices
All of the other choices
QN=35 (7413) File Structure can be: a. Byte sequence b. Record sequence c. Tree d. All of the other choices
All of the other choices
QN=37 (7428) Which are allocation methods of disk blocks for files? a. Contiguous allocation b. Linked allocation c. Indexed allocation d. All of the other choices
All of the other choices
QN=39 (7450) Increasing file system performance is implemented by _____ a. Buffer cache b. Block Read Ahead c. Defragmenting Disks d. All of the other choices
All of the other choices
QN=44 (7485) Which of the following statements about the task of device controller of I/O devices is correct? a. Convert serial bit stream to block of bytes b. Perform error correction as necessary c. Make available to main memory d. All of the other choices
All of the other choices
QN=44 (7498) DMA operations require the following information from the processor a. Address of I/O device b. Starting memory location to read from and write to c. Number of words to be read or written d. All of the other choices
All of the other choices
QN=45 (7489) Which approach is used in order to CPU communicate with the control registers of the I/O device? a. Separating I/O and memory space b. Memory-mapped I/O c. Hybrid: separating I/O and memory space and memory-mapped I/O d. All of the other choices
All of the other choices
QN=53 (7549) A operation concerning Stable Storage is: a. Stable writes b. Stable Reads c. Crash recovery d. All of the other choices
All of the other choices
QN=54 (7576) If a system is deadlocked, no processes can a. run b. release resources c. be awakened d. All of the other choices
All of the other choices
QN=9 (6903) Which of the following is a task of process management of OS? a. Process creation and deletion. b. Process suspension and resume c. Provision of mechanisms for process synchronization, Interprocess communication, Prevent or avoid deadlock d. All of the other choices
All of the other choices
QN=9 (6908) The major operating system services provide mechanisms for secure and efficient are: a. Communication between processes b. File manipulation c. Execution of a program, I/O operations performed by it, and detecting and reporting errors caused by it d. All of the other choices
All of the other choices
QN=27 (7048) Which of these statements about the Inverted Page Table are true? a. An entry contains the pair (process, virtual page) mapped into the corresponding page frame b. An entry contains the pair (process, offset) mapped into the corresponding page frame c. An entry contains the pair (segment, virtual page) mapped into the corresponding page frame d. An entry contains the pair (segment, offset) mapped into the corresponding page frame
An entry contains the pair (process, virtual page) mapped into the corresponding page frame
QN=20 (6999) The first-come, first-served (FCFS) algorithm is fine for most ____ systems a. Interactive b. Batch c. Real time d. Multiuser
Batch
QN=17 (6984) Semaphores that are initialized to 1 and used for two or more processes to ensure only one can enter its critical section at the same time are called: a. Binary semaphores b. Integer semaphores c. Counter semaphores d. None of the other choices
Binary semaphores
QN=41 (7477) Which class of I/O devices that disks and tapes belong to? a. Stream devices b. Block devices c. Character devices d. None of the other choices
Block devices
QN=43 (7475) The main classes of I/O devices are: a. Stream devices b. Block devices c. Character devices d. Block devices and Character devices
Block devices and Character devices
QN=12 (6941) Which of the following process state transitions is correct, when the external event for which a process was waiting happens? a. Running -> Blocked (waiting) b. Running -> ready c. Blocked (waiting) -> ready d. Ready -> running
Blocked (waiting) -> ready
QN=38 (7437) Disk can be divided up into one or more partitions. The first block of every partition is called: a. Free block b. MBR c. Boot block d. Super block
Boot block
QN=24 (7029) Which of the following is a method to keep track of memory usages? a. Memory Management with Bit Maps b. Memory Management with Linked Lists c. Both Memory Management with Bit Maps and Memory Management with Linked Lists d. None of the other choices
Both Memory Management with Bit Maps and Memory Management with Linked Lists
QN=39 (7442) The Linking technique that allows the file to appear in more than one directory are: a. Hard link b. Symbolic link c. Both hard link and symbolic link d. Soft link
Both hard link and symbolic link
Which is not a component of general structure of device drivers? a. Checking the input parameters to see if they are valid b. Checking if the device is currently in use c. Writing command sequence into controller's device registers d. Checking to see if the user is permitted to use the device
Checking to see if the user is permitted to use the device
QN=55 (7581) ____ is when each process involved in the impasse is waiting for another to voluntarily release the resource so that at least one will be able to continue on. a. Mutual-exclusion condition b. Circular-wait condition c. Hold and wait condition d. No preemption condition
Circular-wait condition
QN=11 (6931) OS Win32 use system call_____, while OS Unix use system call______ to create a new process a. CreateProcess; fork b. fork, CreateProcess c. copy, CreateProcess d. CreateProcess; copy
CreateProcess; fork
QN=46 (7495) Which of the following statements is not correct about DMA? a. DMA controller has access to the system bus independent of the CPU b. DMA helps reduce the number of interrupts (in comparison with interrupt-driven I/O) c. DMA controller is usually faster than CPU d. The operating system can only use DMA if the hardware has a DMA controller
DMA controller is usually faster than CPU
QN=57 (7593) The permanent blocking of a set of processes that compete for system resources is called a. Starvation b. Deadlock c. Prioritization d. None of the other choices
Deadlock
QN=48 (7507) Which of the following statements is not correct about "device independence"? a. Files and devices are accessed in the same way, independent of their physical nature b. A system has to maintain only one set of system calls for both writing on a file and writing on the console c. Device independence requires all programmers to deal with different devices directly d. Device independent interfaces should be given to programmers
Device independence requires all programmers to deal with different devices directly
QN=43 (7493) In general, which is the best technique for I/O Data transfer? a. Programmed I/O b. Interrupt-Driven I/O c. Direct Memory Access d. None of the other choices
Direct Memory Access
QN=18 (6987) Which of the following statements is true about hardware solution to the critical region problem? a. Disable Interrupts b. Monitors c. Semaphore d. None of the other choices
Disable Interrupts
QN=52 (7541) What is a "stripping" in RAID? a. Distributing data over multiple drives b. Take away possessions from someone c. Get undressed d. All of the other choices
Distributing data over multiple drives
QN=10 (6912) Which of the following is correct about the advantages of layered system? a. Easier to extend b. Easier to debug from lower to upper layer c. Easier to extend and Easier to debug from lower to upper layer d. None of the other choices
Easier to extend and Easier to debug from lower to upper layer
QN=30 (7077) The ____ policy is based on the theory that the best page to remove is the one that has been in memory the longest a. NRU b. LRU c. FIFO d. LIFO
FIFO
QN=34 (7406) A ____ is a group of related records that contains information to be used by specific application programs to generate reports. a. Field b. Record group c. File d. Directory
File
QN=31 (7080) Working set model is used for: a. Finding the minimum number of frames necessary for a job so that jobs can be run without "thrashing" b. Finding the average number of frames a job will need to run smoothly c. Determining whether page replacement is needed d. All of the other choices
Finding the minimum number of frames necessary for a job so that jobs can be run without "thrashing"
QN=59 (7619) Which deadlock condition does "Request all resources initially" attack? a. Mutual exclusion b. Hold and wait c. No preemption d. Circular-wait condition
Hold and wait
QN=8 (6898) What is not correct about system calls? a. A system call allows a user process to assess and execute operating system functions inside the kernel. b. User programs use system calls to invoke operating system services c. In terms of performance, using system calls is better than using procedure calls d. Every system call involves overhead due to context switch
In terms of performance, using system calls is better than using procedure calls
QN=16 (6973) In order to implement mutual exclusion on a critical resource for competing processes, only one program at a time should be allowed: a. In the critical region of the program b. To perform message passing c. To exhibit cooperation d. None of the other choices
In the critical region of the program
QN=36 (7430) Which of the following allocation methods the i-nodes use? a. Contiguous allocation b. Linked allocation c. Indexed allocation d. Linked allocation using FAT
Indexed allocation
QN=45 (7504) What is the table where its entry contains the memory address of Interrupt service routine a. Interrupt vector table b. Interrupt table c. Address table d. Address lines table
Interrupt vector table
QN=4 (6860) Which of the following statements about Random Access memory (RAM) is correct? a. Is typically faster than cache memory b. Is volatile c. Can only be read sequentially d. Stores all the files on the computer
Is volatile
QN=40 (7449) Which mechanism is implemented by writing to the log file with the purpose of file system management and optimization? a. Journaling File Systems b. Log-Structured File Systems c. Virtual File Systems d. None of the other choices
Journaling File Systems
QN=3 (6855) Booting a general purpose computer involves the following steps except a. Execution of a ROM-based POST sequence b. Loading one or more bootstrap loaders c. Loading the OS d. Loading the command interpreter
Loading the command interpreter
QN=6 (6873) Which is not an example of a resource that is commonly time-multiplexed? a. Network interface b. CPU c. Graphics accelerator d. Main memory
Main memory
QN=24 (7033) Which of these statements about the algorithm "Next fit" is true? a. Memory Manager scans along the list of segments until it finds a hole that is big enough. b. Memory Manager starting searching the list of segments from the place where it left off last time. c. Memory Manager searches the entire list of segments from beginning to end and take smallest hole that is adequate. d. None of the other choices
Memory Manager starting searching the list of segments from the place where it left off last time.
QN=11 (6925) What is the "sequential processes" concept? a. There are both many CPU and many PC b. All process is executed in concurrency c. No concurrency inside a process; everything happens sequentially d. None of the other choices
No concurrency inside a process; everything happens sequentially
QN=15 (6966) Which conditions of mutual exclusion does the Lock Variables (Software proposal) violate? a. No two processes simultaneously in critical region b. No assumptions made about speeds or numbers of CPUs c. No process running outside its critical region may block another process d. No process must wait forever to enter its critical region
No two processes simultaneously in critical region
QN=33 (7092) Which of the following statements about segmentation is false? a. There are several linear address spaces b. The total address space can be more than the size of physical memory c. Sharing of procedures between different users can be facilitated d. None of the other choices
None of the other choices
QN=2 (6847) Which of main bus in the IBM PC computer, that can run at 66 MHz and transfer 8 bytes at a time? a. ISA (Industry Standard Architecture) b. PCI (Peripheral Component Interconnect) c. ISA and PCI d. None of the other choices
PCI (Peripheral Component Interconnect)
QN=26 (7045) When a virtual memory system manages memory in fixed length units, which of the following terms correctly represents its unit? a. Frame b. Page c. Block d. Segment
Page
QN=33 (7408) Which of the following is specified to indicate the directory where the file is located? a. Extension b. Path name c. Root directory d. Sub-directory
Path name
QN=19 (6991) What is the purpose of CPU scheduling algorithms? a. Pick one of the ready processes to run next b. Put to sleep and wake up processes in an efficient manner c. Allocate memory to the processes in a fair and efficient way d. None of the other choices
Pick one of the ready processes to run next
QN=14 (6959) An arrival message causes the system to create a new thread to handle this message. This new thread is call______ a. Pop-up b. Upcall c. Activator d. Distributed
Pop-up
QN=47 (7502) An interrupt that leaves the machine in well-defined state is called a(n) ______ a. Precise interrupt b. Imprecise interrupt c. Required interrupt d. Disappointed interrupt
Precise interrupt
QN=2 (6843) The four main structural elements of a computer system are: a. Processor, Registers, I/O Modules, Main Memory b. Processor, Registers, Main Memory, System Bus c. Processor, Main Memory, I/O Modules, System Bus d. None of the other choices
Processor, Main Memory, I/O Modules, System Bus
QN=1 (6840) Which of special register contains the Mode Bit (user or kernel)? a. Instruction Register (IR) b. Program Counter (PC) c. Program Status Word (PSW) d. None of the other choices
Program Status Word (PSW)
QN=6 (6871) What is not a main function of an operating system? a. Provide the users with an extended (virtual) machine b. Manage the I/O devices c. Provide user interfaces d. Support virtual memory
Provide user interfaces
QN=7 (6888) A well-known Embedded operating system is: a. TinyOS b. QNX and VxWork c. Symbian OS and Palm OS d. e-COS
QNX and VxWork
QN=3 (6849) Which of the following instructions should be allowed in user mode? a. Disable all interrupts b. Read the time-of-day clock c. Set the time-of-day clock d. Change the memory map
Read the time-of-day clock
QN=12 (6944) Which of the following process state transitions is illegal? a. Running -> Blocked (waiting) b. Running -> ready c. Blocked (waiting) -> ready d. Ready -> Blocked (waiting)
Ready -> Blocked (waiting)
QN=32 (7086) Which is not true about the method of backing store: "Paging to a static swap area"? a. The swap area on the disk is as large as the process virtual address space b. Calculating the address in swap area requires knowing only where the process' paging area begins c. Requires a disk map in memory d. A page that is in memory always have shadow copy on disk
Requires a disk map in memory
QN=19 (6994) Which is not a goal of a scheduling algorithm for batch systems? a. CPU utilization b. Throughput c. Turnaround time d. Response time
Response time
QN=49 (7531) Of the three components of access time in a disk, ____ is the longest. a. Seek time b. Search time c. Transfer time d. Delay time
Seek time
QN=18 (6988) Which cannot be able to solve the race condition? a. TSL b. Shared memory c. Semaphore d. Monitor
Shared memory
QN=23 (7021) Which of following is true about cache in the memory hierarchy? a. Small amount of fast expensive memory b. Some medium-speed medium price c. Gigabytes of slow cheap memory d. None of the other choices
Small amount of fast expensive memory
QN=37 (7438) The disk block in a partition that includes a magic number, the number of blocks in the file system and other key administrative information is called: a. Free block b. MBR c. Boot block d. Superblock
Superblock
QN=1 (6836) A CPU may have multiple execution units, so that can carry out multiple instructions in the same time is called: a. Pipeline b. Superscalar c. Multicore d. None of the other choices
Superscalar
QN=38 (7444) Which of the following is correct about symbolic links? a. Symbolic links need not space to store the path name b. Symbolic links can only point to files on the same machines c. Symbolic links can point to files in the network d. None of the other choices
Symbolic links can point to files in the network
QN=16 (6969) Which of the following statements is a hardware solution to the critical region problem? a. TSL b. Shared memory c. Semaphore d. None of the other choices
TSL
QN=60 (7624) What is the correct approach with the "No preemption condition" to prevent Deadlock? a. Order resources numerically b. Request all resources initially c. Spool everything d. Take resources away
Take resources away
QN=41 (7454) The File Manager writes the volume name and other descriptive information on an easy-to-access place on each unit: ____ of the CD or DVD a. The outermost part b. The innermost part c. Immediately following the master file directory d. Stored at the beginning of the volume
The innermost part
QN=40 (7456) Which of the following is true about the block size in disk space management a. The larger the block size is the lower the data rate is b. The larger the block size is the worse the disk space utilization is c. The larger the block size is lesser the disk space is d. None of the other choices
The larger the block size is the worse the disk space utilization is
QN=23 (7028) With paging, when is the internal fragmentation possible? a. Page does not fit the frame b. The last page of the job is less than the maximum page size c. The virtual memory assigned to the program is less than the physical memory assigned to it d. Such thing cannot happen
The last page of the job is less than the maximum page size
QN=5 (6867) Which of the following statements is incorrect about the CMOS? a. Is volatile b. To hold the current time and date c. To contain BIOS d. To hold the configuration parameters
To contain BIOS
QN=34 (7417) Which of the following file structure is widely used on large mainframe computers? a. Byte sequence b. Record sequence c. Ring d. Tree
Tree
QN=49 (7514) Which is the right order between the 4 I/O software layers? a. User-level I/O software, Device drivers, Interrupt handlers, Device-independent OS software b. User-level I/O software, Interrupt handlers, Device drivers, Device-independent OS software c. Device-independent OS software, user-level I/O software, Device drivers, Interrupt handlers d. User-level I/O software, Device-independent OS software, Device drivers, Interrupt handlers
User-level I/O software, Device-independent OS software, Device drivers, Interrupt handlers
QN=26 (7042) One of the most important innovations of demand paging was that it made ____ feasible a. Memory demand b. Virtual demand c. Virtual paging d. Virtual memory.
Virtual memory.
QN=32 (7089) In terms of main memory efficiency the method of "Backing up pages dynamically" in comparison with the method of "Paging to a static swap area" is a. Better b. Worse c. Equal d. Nearly equal
Worse
QN=47 (7518) Which of the following I/O software do Device drivers do? a. Converting binary integers to ASCII for printing b. Writing commands to the device registers c. Checking to see if the user is permitted to use the device d. None of the other choices
Writing commands to the device registers
QN=50 (7523) Each device attached to your computer comes with a special program called a __________ that facilitates the communication between the device and the OS. a. device configurator b. translator c. device driver d. communication utility
device driver
QN=8 (6899) A(n) _________ is provided to make system calls from some programming languages a. procedure library b. operator c. pointer d. None of the other choices
procedure library
QN=31 (7081) When there is an excessive amount of page swapping between main memory and secondary storage, the operation becomes inefficient, which is called ____. a. excessive demand paging b. hot swapping c. thrashing d. Over swapping
thrashing
QN=51 (7528) In a fixed magnetic disk, each circle is called a ____. a. sector b. block c. track d. platter
track