WGU C191 Programmers Operating
Systems Competency study guide Exam
test questions with approved Answers
2024/2025
Logical Formatting - correct answer the creation of a file system.
Network Attached Storage (NAS) - correct answer A special-purpose storage system
that is accessed remotely over a data network.
Solid State Disk (SSD) - correct answer Utilizes non-volatile memory (DRAM) to
behave like a traditional disk drive but utilizes no moving parts. Has no latency or seek
times.
File - correct answer A logical storage unit as defined by the OS.
Text File - correct answer A sequence of characters organized into lines, possibly
pages.
Source File - correct answer A sequence of functions, further organized as
declarations followed by an executable statement.
Executable File - correct answer A series of code sections that the loader can bring
into memory and execute.
Name - correct answer A file attribute defining the symbolic file name in human-
readable format.
Identifier - correct answer A unique tag which identifies a file within the file system in
non-human-readable format.
,Open-File Table - correct answer An OS table containing information about all open
files.
Sequential Access - correct answer An access method where the information in the file
is processed in order, one record after another.
Direct Access - correct answer An access method allowing programs to read and write
records rapidly in no particular order.
Sector - correct answer A subdivision of a track, usually 512 bytes.
Track - correct answer A circular path on the surface of a disk, broken up into sectors.
Cluster - correct answer Multiple blocks grouped together.
Block - correct answer A sector or group of sectors that the operating system can
address. The smallest unit of transfer.
Common File Attributes - correct answer Name, identifier, type, location, size,
protection, time, date, and user information.
Control Register - correct answer Can be written to by the host to start a command or
to change the mode of an I/O device.
Status Register - correct answer Contains bits that can be read by the host to convey
the status of I/O devices.
Data-Out Register - correct answer Written by the host to send output to I/O devices.
Data-In Register - correct answer Read by the host to get input from I/O devices.
,Constant Linear Velocity (CLV) - correct answer Where the density of bits per track is
uniform and the speed changes.
Constant Angular Velocity (CAV) - correct answer The density of bits decreases from
inner tracks to outer tracks to keep the data rate constant.
Low-Level Formatting (Physical Formatting) - correct answer Divides and fills the disk
with a special data structure for each sector. Must be done before a disk can store data.
PCI Express (PCIe) - correct answer Has a throughput of up to 16 GB per second.
HyperTransport - correct answer Has a throughput of up to 25 GB per second.
Interrupt-Controller Hardware Features - correct answer The ability to defer interrupt
handling during critical processing.
An efficient way to dispatch to the proper interrupt handler for a device without first
polling all the devices to see which one raised the interrupt.
Multilevel interrupts, so that the operating system can distinguish between high- and
low-priority interrupts and can respond with the appropriate degree of urgency.
Direct Memory Access (DMA) Controller - correct answer A special processor that
avoids programmed I/O by writing a command block into memory. This block contains a
pointer to the source of a transfer, a pointer to the destination of the transfer, and a
count of the number of bytes to be transferred. The CPU writes the address of this
command block to the controller.
Block-Device Interface - correct answer Captures all the aspects necessary for
accessing disk drives and other block-oriented devices.
, Character-Stream Interface - correct answer A set of basic system calls that an
application can use to get() or put() one character.
Raw - correct answer I/O accesses a block device as a simple array of blocks,
bypasses all file system services.
Contiguous Allocation - correct answer File occupies a set of contiguous blocks on the
disk and can be accessed using sequential or direct access.
Blocking System Call - correct answer Wherein the execution of the application is
suspended.
Spool - correct answer A buffer that holds output for a device that cannot accept
interleaved data streams.
Sense Key - correct answer Identifies the general nature for a failure in a SCSI device.
Additional Sense Code - correct answer States the category of failure, such as a bad
command parameter or a self-test failure.
Additional Sense Code Qualifier - correct answer Gives even more detail, such as
which command parameter was in error or which hardware subsystem failed its self-
test.
Terminal Concentrator - correct answer A front-end processor that multiplexes the
traffic from hundreds of remote terminals into one port on a large computer.
Local I/O Ports - correct answer Where host-attached storage is accessed.
I/O Processing Improvement - correct answer Can be done by moving processing
primitives into hardware.
Systems Competency study guide Exam
test questions with approved Answers
2024/2025
Logical Formatting - correct answer the creation of a file system.
Network Attached Storage (NAS) - correct answer A special-purpose storage system
that is accessed remotely over a data network.
Solid State Disk (SSD) - correct answer Utilizes non-volatile memory (DRAM) to
behave like a traditional disk drive but utilizes no moving parts. Has no latency or seek
times.
File - correct answer A logical storage unit as defined by the OS.
Text File - correct answer A sequence of characters organized into lines, possibly
pages.
Source File - correct answer A sequence of functions, further organized as
declarations followed by an executable statement.
Executable File - correct answer A series of code sections that the loader can bring
into memory and execute.
Name - correct answer A file attribute defining the symbolic file name in human-
readable format.
Identifier - correct answer A unique tag which identifies a file within the file system in
non-human-readable format.
,Open-File Table - correct answer An OS table containing information about all open
files.
Sequential Access - correct answer An access method where the information in the file
is processed in order, one record after another.
Direct Access - correct answer An access method allowing programs to read and write
records rapidly in no particular order.
Sector - correct answer A subdivision of a track, usually 512 bytes.
Track - correct answer A circular path on the surface of a disk, broken up into sectors.
Cluster - correct answer Multiple blocks grouped together.
Block - correct answer A sector or group of sectors that the operating system can
address. The smallest unit of transfer.
Common File Attributes - correct answer Name, identifier, type, location, size,
protection, time, date, and user information.
Control Register - correct answer Can be written to by the host to start a command or
to change the mode of an I/O device.
Status Register - correct answer Contains bits that can be read by the host to convey
the status of I/O devices.
Data-Out Register - correct answer Written by the host to send output to I/O devices.
Data-In Register - correct answer Read by the host to get input from I/O devices.
,Constant Linear Velocity (CLV) - correct answer Where the density of bits per track is
uniform and the speed changes.
Constant Angular Velocity (CAV) - correct answer The density of bits decreases from
inner tracks to outer tracks to keep the data rate constant.
Low-Level Formatting (Physical Formatting) - correct answer Divides and fills the disk
with a special data structure for each sector. Must be done before a disk can store data.
PCI Express (PCIe) - correct answer Has a throughput of up to 16 GB per second.
HyperTransport - correct answer Has a throughput of up to 25 GB per second.
Interrupt-Controller Hardware Features - correct answer The ability to defer interrupt
handling during critical processing.
An efficient way to dispatch to the proper interrupt handler for a device without first
polling all the devices to see which one raised the interrupt.
Multilevel interrupts, so that the operating system can distinguish between high- and
low-priority interrupts and can respond with the appropriate degree of urgency.
Direct Memory Access (DMA) Controller - correct answer A special processor that
avoids programmed I/O by writing a command block into memory. This block contains a
pointer to the source of a transfer, a pointer to the destination of the transfer, and a
count of the number of bytes to be transferred. The CPU writes the address of this
command block to the controller.
Block-Device Interface - correct answer Captures all the aspects necessary for
accessing disk drives and other block-oriented devices.
, Character-Stream Interface - correct answer A set of basic system calls that an
application can use to get() or put() one character.
Raw - correct answer I/O accesses a block device as a simple array of blocks,
bypasses all file system services.
Contiguous Allocation - correct answer File occupies a set of contiguous blocks on the
disk and can be accessed using sequential or direct access.
Blocking System Call - correct answer Wherein the execution of the application is
suspended.
Spool - correct answer A buffer that holds output for a device that cannot accept
interleaved data streams.
Sense Key - correct answer Identifies the general nature for a failure in a SCSI device.
Additional Sense Code - correct answer States the category of failure, such as a bad
command parameter or a self-test failure.
Additional Sense Code Qualifier - correct answer Gives even more detail, such as
which command parameter was in error or which hardware subsystem failed its self-
test.
Terminal Concentrator - correct answer A front-end processor that multiplexes the
traffic from hundreds of remote terminals into one port on a large computer.
Local I/O Ports - correct answer Where host-attached storage is accessed.
I/O Processing Improvement - correct answer Can be done by moving processing
primitives into hardware.
