PA Flashcards
What is an operating system?
An application that runs on bare hardware
An application that runs within a kernel
Software that runs on bare hardware
Software that runs within a kernel
Software that runs on bare hardware
Which type of CPU instruction sets are supported by the CPU user mode?
Both privileged and non-privileged
Neither privileged nor non-privileged
Only privileged
Only non-privileged
Only non-privileged
What are two locations where firmware can be stored?
Choose 2 answers.
Flash memory
Read-only memory (ROM)
Cache memory
Dynamic random-access memory (DRAM)
Flash memory
Read-only memory (ROM)
Which generation of computers were large-scale integrated circuits used to develop personal computers for desktop and laptop operating systems?
2nd
3rd
4th
5th
4th
A company requires a computing environment that supports high-volume data processing and the management of a large amount of storage.
Which computing environment should the company use?
Desktop
Server
Laptop
Mainframe
Mainframe
What is a system service?
A component of an operating system responsible for memory management
A set of files used to store and retrieve operating system configuration information
A program designed for end-user execution in the operating system
An application included with an operating system to provide functionality beyond the kernel
An application included with an operating system to provide functionality beyond the kernel
A company needs to determine when a computer experiences a microprocessor interrupt that is the result of a division by zero.
Which operating system service should be used?
Communication
Error detection
Logging
Deadlock detection
Error detection
Which interface allows combining multiple programs using the output from one as the input to another?
Graphical user interface (GUI)
Voice-user interface (VUI)
Command-line interface (CLI)
Natural user interface (NUI)
Command-line interface (CLI)
Which command is used to determine the number of lines in a file?
copy
dir
wc
del
wc
Which cyberattack prevents a legitimate user from accessing an application in a timely manner?
Denial-of-service
Information disclosure
Unauthorized use
Information destruction
Denial-of-service
Which operating environment is used to run an embedded system?
Mainframe
Server
Desktop
Real-time
Real-time
Which component is responsible for running and suspending tasks in a multitasking operating system?
Memory manager
Network manager
Process manager
Storage manager
Process manager
What is a thread?
System component allowed to run a privileged instruction set
Part of a process that can run concurrently with other parts
Application providing a user interface to system calls
Instantiation of a process with a unique identifier
Part of a process that can run concurrently with other parts
What are the two properties of threads?
Choose 2 answers.
Using multiple processes within a thread is more efficient than using multiple threads
Using multiple threads within a process is more efficient than using multiple processes
User-level threads are faster to manage than kernel-level threads
Kernel-level threads are faster to manage than user-level threads
Using multiple threads within a process is more efficient than using multiple processes
User-level threads are faster to manage than kernel-level threads
Which resource is virtualized by multitasking?
Disk
Memory
Network
Processor
Processor
Which technique is used to execute several jobs by time-sharing among them?
Multitasking
Multiprogramming
Abstraction
Virtualization
Multitasking
What is a computer program in execution called?
Trap
Thread
Task
Process
Process
What is the relationship between threads, processes, and global data?
All threads within a process share the same copy of global data.
All processes within a thread share the same copy of global data.
Each thread within a process has its own copy of global data.
Each process within a thread has its own copy of global data.
All threads within a process share the same copy of global data.
What does each thread of a multi-threaded process use to access shared code?
Kernel
Application
Program counter
Stack pointer
Program counter
What is a critical section?
An area of code that cannot be entered by a process while another process is executing a corresponding area of the code.
An area of code that cannot be modified by the operating system.
An area of code that can be entered by a process while another process is executing a corresponding area of the code.
An area of code that can be modified by the operating system.
An area of code that cannot be entered by a process while another process is executing a corresponding area of the code.
How do threads differ from processes?
Threads may contain multiple processes.
Threads execute portions of a program within a process.
Processes are faster to destroy than threads.
Processes execute portions of a program within a thread.
Threads execute portions of a program within a process.
Which scheduler is used to decide the ready processes that should run next on the CPU?
Long-term
Short-term
Preemptive
Non-preemptive
Short-term
A process is not attempting to enter the critical section (CS), but it is preventing other processes from entering the CS.
Which situation was caused by this process?
Concurrency
Starvation
Lockout
Deadlock
Lockout
Which step is completed first during an input/output (I/O) call?
The direct memory access controller transfers data to kernel memory
The interrupt handler signals device driver
The process is placed on the wait queue
The device driver allocates kernel buffer space
The process is placed on the wait queue
Which free memory space management strategy allocates the smallest free partition that meets the requirement of the requesting process?
Best fit
First fit
Next fit
Worst fit
Best fit
Which method does the operating system use to divide system memory into contiguous, equal-sized partitions?
Fragmentation
Relocation
Paging
Swapping
Paging
What is the physical memory size for an address size of 8 bits?
16
64
256
1,024
256
What causes a page fault?
Modified bit is set to 0
Present bit is set to 1
Present bit is set to 0
Modified bit is set to 1
Present bit is set to 0
What should be used to improve memory utilization when loading external references?
Dynamic linking
Static linking
Swapping
Compaction
Dynamic linking
Why are approximations used in place of the least-recently-used (LRU) algorithm?
Higher precision
Higher efficiency
Selects longest unused pages
Guarantees fewer page faults
Higher efficiency
What describes the 50% rule in external memory fragmentation?
One-fourth of memory may be lost.
One-fourth of memory is occupied.
One-third of memory may be lost.
One-third of memory is occupied.
One-third of memory may be lost.
What describes the difference between internal and external fragmentation?
Choose 2 answers.
External fragmentation occurs when memory blocks are divided into variable-sized partitions.
External fragmentation occurs when memory blocks are divided into fixed-sized partitions.
Internal fragmentation occurs when memory blocks are divided into fixed-sized partitions.
Internal fragmentation occurs when memory blocks are divided into variable-sized partitions.
External fragmentation occurs when memory blocks are divided into variable-sized partitions.
Internal fragmentation occurs when memory blocks are divided into fixed-sized partitions.
What does the memory manager do that can lead to poor system performance?
Choose 2 answers.
Fails to allocate memory as needed, causing processes to crash
Is unable to allocate contiguous free blocks as needed, causing processes to wait
Suspends processes requesting memory, causing them to stop responding
Is forced to compact memory so it can fulfill allocations, causing processes to wait
Is unable to allocate contiguous free blocks as needed, causing processes to wait
Is forced to compact memory so it can fulfill allocations, causing processes to wait
What are two effects of paging in the address space?
Choose 2 answers.
Permits the physical address of a process to be noncontiguous
Divides the logical address space of a process into equal-sized partitions
Creates unused address spaces called external fragmentation
Divides the logical address space of a process into different-sized partitions
Permits the physical address of a process to be noncontiguous
Divides the logical address space of a process into equal-sized partitions
What is a page in memory management?
Fixed-size contiguous block of a logical address space identified by a single number
Fixed-size contiguous block of physical memory identified by a single number
Variable-size noncontiguous block of physical memory identified by a single number
Variable-size noncontiguous block of a logical address space identified by a single number
Fixed-size contiguous block of a logical address space identified by a single number
What is used to determine the number of processes that can run concurrently?
Memory segmentation
Demand paging
Scheduling
Load control
Load control
What are the two measures of positioning time?
Choose 2 answers.
Moving the disk arm to the desired cylinder
Rotating the desired sector to the disk head
Transferring data from the disk to the host system
Transferring data to and from the disk media
Moving the disk arm to the desired cylinder
Rotating the desired sector to the disk head
A company needs to ensure consistent performance by decreasing the density of bits from inner tracks to outer tracks.
Which hard disk method should be used?
Constant angular acceleration
Constant angular velocity
Constant linear velocity
Constant magnetic field
Constant angular velocity
Which disk type provides direct access to a secondary storage device as an array of blocks with no file system?
Boot
Raw
Virtual
Swap
Raw
What is an advantage of swapping?
Provides efficient usage of memory by deallocating dynamic space when processes complete and allocating memory at run time
Provides efficient usage of memory by reducing external fragmentation on a computer
Allows processes that load the same DLL at the same base address to share a single copy of the DLL in physical memory
Allows computers to execute more processes than there is available physical memory on a computer
Allows computers to execute more processes than there is available physical memory on a computer
Which file attribute should be used to identify who can access a file?
Location
Protection
Type
Size
Protection
Which scheduling system should be used to stop a process that is currently running and select another process to run?
Long-term
Short-term
Preemptive
Non-preemptive
Preemptive
Which data structure represents the allocation status of each disk block?
Queue
Linked list
Bitmap
Binary tree
Bitmap
Which latency waits for the requested data to pass under the drive head of a magnetic hard disk?
Seek time
Sector overhead time
Peak transfer rate
Rotational delay
Rotational delay
What is the determining factor for sustained throughput in magnetic storage?
Disk size
Track seek time
Data transfer rate
Rotational latency
Data transfer rate
What can be used to access Dropbox?
Common Internet File System - CIFS
Internet Small Computer System Interface - iSCSI
Network-attached storage - NAS
Application programming interface - API
Application programming interface - API
What is a direct memory access (DMA) controller?
Program invoked by the driver to access main memory
Hardware device allowing access of main memory without the CPU
Hardware device used by the CPU to access main memory
Program invoked by the CPU to access main memory
Hardware device allowing access of main memory without the CPU
What is partitioning?
Changing the type of file system in a storage region
Changing the size of blocks
Reallocating blocks into a contiguous space
Creating groups of blocks on secondary storage
Creating groups of blocks on secondary storage
Which user authentication method has the form of a dialogue between user and system?
One-time password
Challenge-response
Single sign-on
Biometrics
Challenge-response
What provides asymmetric cryptography?
Lempel-Ziv-Markov Algorithm (LZMA)
Rivest-Shamir-Adleman (RSA)
Data Encryption Standard (DES)
Advanced Encryption Standard (AES)
Rivest-Shamir-Adleman (RSA)
What is a symmetric key algorithm?
Data encryption standard (DES)
Huffman code
Hamming code
Rivest-Shamir-Adleman (RSA)
Data encryption standard (DES)
An access matrix list of three domains and six objects is depicted in the following table:
O1 O2 O3 O4 O5 O6
D1 r rwx
D2 rwx rwx r r
D3 rwxo rwx rwxo rwx rwxo
What is the length of the shortest capability list?
1
2
4
5
2
An access matrix list of three domains and six objects is depicted in the following table:
O1 O2 O3 O4 O5 O6
D1 r rwx
D2 rwx rwx r r
D3 rwxo rwx rwxo rwx rwxo
What is the length of the shortest access list?
1
2
4
5
1
Which two techniques guard against unauthorized activities when running code written by others?
Choose 2 answers.
Sandboxing
Compiling
Compression
Interpretation
Sandboxing
Interpretation
What is a key that is used by a recipient to decrypt a message encrypted with asymmetric encryption?
Public
Private
Shared
Hash
Private
What is the benefit of asymmetric cryptography?
Faster encryption and decryption operations
No need to exchange secret keys
Uses the same key for encryption and decryption
Higher computational complexity of encryption and decryption
No need to exchange secret keys
When should digests be used?
Establishing an undeniable link between the document and its sender
Accelerating document encryption
Reducing encrypted document size
Reducing computational complexity of document decryption
Establishing an undeniable link between the document and its sender
Which technique involves requesting an unsuspecting user to disclose their credit card information on a fake website that looks legitimate?
Logic bomb
Login spoofing
Phishing
Trapdoor
Phishing
Which technique is used to bypass user authentication?
Buffer overflow
Login spoofing
Back door
Phishing
Back door
Which cyberattack technique is mitigated by using the CTRL+ALT+DEL key sequence in the Windows operating systems?
Back door
Information leaking
Logic bomb
Login spoofing
Login spoofing
