Page 200 - DCAP103_Principle of operating system

Unit 5: Memory Management

Self Assessment Notes

Multiple choice questions:

4. Virtual memory is ..................... .
( a) An extremely large main memory
( b) An extremely large secondary memory
( c) An illusion of extremely large main memory
( d) A type of memory used in super computers.
5. The problem of thrashing is effected scientifically by ..................... .
( a) Program structure

( b) Program size
( c) Primary storage size
( d) None of the above

6. The mechanism that bring a page into memory only when it is needed is called
..................... .

( a) Segmentation
( b) Fragmentation
( c) Demand Paging

( d) Page Replacement
7. The Memory Buffer Register (MBR)

( a) is a hardware memory device which denotes the location of the current instruction
being executed.

( b) is a group of electrical circuits (hardware), that performs the intent of instructions
fetched from memory.

( c) contains the address of the memory location that is to be read from or stored into.
( d) contains a copy of the designated memory location specified by the MAR after a
“read” or the new contents of the memory prior to a “write”.
8. The LRU algorithm
( a) pages out pages that have been used recently.

( b) pages out pages that have not been used recently.
( c) pages out pages that have been least used recently.

( d) pages out the first page in a given area.
9. Thrashing
( a) is a natural consequence of virtual memory systems.
( b) can always be avoided by swapping.
( c) always occurs on large computers.
( d) can be caused by poor paging algorithms.

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