WGU D686 OPERATING SYSTEMS
OBJECTIVE EVALUATION OA VERSION
ONE AND TWO 2026 COMPREHENSIVE
QUESTIONS AND VERIFIED SOLUTIONS
UPDATED 100 PERCENT CORRECT
GRADED A+
⩥ What is logical memory? Answer: Virtual memory; allows programs
to use more memory than physically available.
⩥ What is volatile memory? Answer: Loses data when power is lost
(e.g., RAM).
⩥ What is nonvolatile memory? Answer: Retains data without power
(e.g., SSD, HDD).
⩥ What is DMA (Direct Memory Access)? Answer: Allows devices to
transfer data to/from memory without CPU intervention; used for fast
data transfer.
⩥ What is page replacement? Answer: Swapping out pages from
memory to make room for new ones.
, ⩥ What is page fault rate? Answer: Frequency at which requested pages
are not in memory.
⩥ What is the best page replacement algorithm? Answer: Optimal
algorithm (replaces page that won't be used for longest time).
⩥ What is FIFO in page replacement? Answer: First-In, First-Out; oldest
page is replaced first.
⩥ What is LRU in page replacement? Answer: Least Recently Used;
replaces page not used for longest time.
⩥ What is a valid-invalid bit? Answer: Indicates if a page is in memory
(valid) or not (invalid).
⩥ What is Belady's anomaly? Answer: More frames can lead to more
page faults in FIFO algorithm.
⩥ What is the Working-Set Model? Answer: Tracks active set of pages
used by process to reduce faults.
⩥ What is the difference between global and local replacement? Answer:
Global allows page replacement from any process; local restricts to
process's own pages.
OBJECTIVE EVALUATION OA VERSION
ONE AND TWO 2026 COMPREHENSIVE
QUESTIONS AND VERIFIED SOLUTIONS
UPDATED 100 PERCENT CORRECT
GRADED A+
⩥ What is logical memory? Answer: Virtual memory; allows programs
to use more memory than physically available.
⩥ What is volatile memory? Answer: Loses data when power is lost
(e.g., RAM).
⩥ What is nonvolatile memory? Answer: Retains data without power
(e.g., SSD, HDD).
⩥ What is DMA (Direct Memory Access)? Answer: Allows devices to
transfer data to/from memory without CPU intervention; used for fast
data transfer.
⩥ What is page replacement? Answer: Swapping out pages from
memory to make room for new ones.
, ⩥ What is page fault rate? Answer: Frequency at which requested pages
are not in memory.
⩥ What is the best page replacement algorithm? Answer: Optimal
algorithm (replaces page that won't be used for longest time).
⩥ What is FIFO in page replacement? Answer: First-In, First-Out; oldest
page is replaced first.
⩥ What is LRU in page replacement? Answer: Least Recently Used;
replaces page not used for longest time.
⩥ What is a valid-invalid bit? Answer: Indicates if a page is in memory
(valid) or not (invalid).
⩥ What is Belady's anomaly? Answer: More frames can lead to more
page faults in FIFO algorithm.
⩥ What is the Working-Set Model? Answer: Tracks active set of pages
used by process to reduce faults.
⩥ What is the difference between global and local replacement? Answer:
Global allows page replacement from any process; local restricts to
process's own pages.
