OPERATING SYSTEMS FOR PROGRAMMERS
WGU C191 PRACTICE PRE ASSESSMENT
2026 UPDATED QUESTIONS AND
SOLUTIONS GRADED A+
⩥ Base Register.
Answer: A memory register that holds the smallest, legal physical-
memory address.
⩥ Limit Register.
Answer: A memory register that specifies the size of the range.
⩥ Input Queue.
Answer: The processes on the disk that are waiting to be brought into
memory for execution.
⩥ Swapping.
Answer: When a process is moved temporarily out of memory to a
backing store.
⩥ Least Recently Used (LRU).
,Answer: A page-replacement algorithm that uses the last time the page
was accessed. The most commonly used page-replacement algorithm.
⩥ Belady's Anomaly.
Answer: States that for some page replacement algorithms, the page
fault rate may increase as the number of allocated frames increases.
⩥ First Fit.
Answer: A type of allocation that finds the first hole that is big enough.
Searching can start at the beginning of the set of holes or at the location
where the previous search ended.
⩥ Best Fit.
Answer: A type of allocation that finds the smallest hole that is big
enough. The entire list must be searched unless the list is ordered by
size. Produces the smallest leftover hole.
⩥ Worst Fit.
Answer: A type of allocation that finds the largest hole. The entire list
must be searched unless it is sorted by size. Produces the largest leftover
hole which may be more useful than the smaller leftover hole from a
different approach.
⩥ Optimal.
,Answer: A page-replacement algorithm that has the lowest page-fault
rate of all algorithms and will never suffer from Belady's anomaly.
⩥ Thrashing.
Answer: Occurs when a process spends more time paging than
executing.
⩥ Segmentation.
Answer: A memory-management scheme that supports the programmers
view of memory.
⩥ Slab.
Answer: Made up of one or more physically contiguous pages.
⩥ Slab Allocation.
Answer: An algorithm that uses caches to store kernel objects and
produces no memory fragmentation.
⩥ Memory Mapping.
Answer: Allows a part of the virtual address space to be logically
associated with the file.
⩥ Address Space Identifier.
, Answer: Allows a part of the virtual address space to be logically
associated with the file.
⩥ Translation Look-Aside Buffer (TLB).
Answer: A small, fast lookup hardware cache that consists of a key (or
tag) and a value. When the associative memory is presented with an
item, the item is compared with all keys simultaneously. If the item is
found, the corresponding value field is returned.
⩥ Non-Uniform Memory Access.
Answer: Wherein memory access times vary significantly.
⩥ Hashed Page Table.
Answer: Good for address spaces larger than 32 bits.
⩥ Clustered Page Table.
Answer: Similar to a hashed page table except that each entry in the hash
table refers to several pages (such as 16) rather than a single page.
⩥ IOS Swapping.
Answer: Asks applications to voluntarily relinquish allocated memory.
⩥ Android Swapping.
WGU C191 PRACTICE PRE ASSESSMENT
2026 UPDATED QUESTIONS AND
SOLUTIONS GRADED A+
⩥ Base Register.
Answer: A memory register that holds the smallest, legal physical-
memory address.
⩥ Limit Register.
Answer: A memory register that specifies the size of the range.
⩥ Input Queue.
Answer: The processes on the disk that are waiting to be brought into
memory for execution.
⩥ Swapping.
Answer: When a process is moved temporarily out of memory to a
backing store.
⩥ Least Recently Used (LRU).
,Answer: A page-replacement algorithm that uses the last time the page
was accessed. The most commonly used page-replacement algorithm.
⩥ Belady's Anomaly.
Answer: States that for some page replacement algorithms, the page
fault rate may increase as the number of allocated frames increases.
⩥ First Fit.
Answer: A type of allocation that finds the first hole that is big enough.
Searching can start at the beginning of the set of holes or at the location
where the previous search ended.
⩥ Best Fit.
Answer: A type of allocation that finds the smallest hole that is big
enough. The entire list must be searched unless the list is ordered by
size. Produces the smallest leftover hole.
⩥ Worst Fit.
Answer: A type of allocation that finds the largest hole. The entire list
must be searched unless it is sorted by size. Produces the largest leftover
hole which may be more useful than the smaller leftover hole from a
different approach.
⩥ Optimal.
,Answer: A page-replacement algorithm that has the lowest page-fault
rate of all algorithms and will never suffer from Belady's anomaly.
⩥ Thrashing.
Answer: Occurs when a process spends more time paging than
executing.
⩥ Segmentation.
Answer: A memory-management scheme that supports the programmers
view of memory.
⩥ Slab.
Answer: Made up of one or more physically contiguous pages.
⩥ Slab Allocation.
Answer: An algorithm that uses caches to store kernel objects and
produces no memory fragmentation.
⩥ Memory Mapping.
Answer: Allows a part of the virtual address space to be logically
associated with the file.
⩥ Address Space Identifier.
, Answer: Allows a part of the virtual address space to be logically
associated with the file.
⩥ Translation Look-Aside Buffer (TLB).
Answer: A small, fast lookup hardware cache that consists of a key (or
tag) and a value. When the associative memory is presented with an
item, the item is compared with all keys simultaneously. If the item is
found, the corresponding value field is returned.
⩥ Non-Uniform Memory Access.
Answer: Wherein memory access times vary significantly.
⩥ Hashed Page Table.
Answer: Good for address spaces larger than 32 bits.
⩥ Clustered Page Table.
Answer: Similar to a hashed page table except that each entry in the hash
table refers to several pages (such as 16) rather than a single page.
⩥ IOS Swapping.
Answer: Asks applications to voluntarily relinquish allocated memory.
⩥ Android Swapping.
