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04 - Virtual Memory

 1. What is virtual memory?

  Long-term memory

  Process for encoding information

  Large secondary memory

  A memory management technique that creates the illusion of a very large (main) memory

 2. Where is data stored when it is in virtual memory?
vm1.png

  A secondary storage device e.g. hard disk drive

  ROM

  An optical drive e.g. CD

  RAM

 3. When several programs run at the same time, the RAM can be full. Instead of closing programs, the operating system uses virtual memory to store some data.

  True

  False

 4. Read/Write speed of a hard disk drive is faster than RAM.
vm2.jpg

  TRUE

  FALSE

 5. Fill in the blanks.
Because of virtual memory, the memory can be shared 
among___________________.

  instructions

  threads

  none of the mentioned

  processes

 6. Hard drive failure rates are measured with MTBF (Mean Time Between Failures). Which of these failures would be reason to replace your current hard disk?

  Application removal

  File delete

  Head crash

  Can't read CDs

 7. Fill in the blanks.
A virtual memory block is known as page, and a virtual-memory miss is 
called a________________.

  hit miss

  page fault

  page miss

  memory fault

 8. Effective access time is directly proportional to:

  memory access time

  page-fault rate

  none of these mentioned

  hit ratio

 9. Virtual memory frees applications from managing shared memory and saves users from adding more memory modules when RAM space runs out.
vm3.jpg

  FALSE

  TRUE

 10. Fill in the blanks.
The address location in the main memory, is referred to 
as____________________.

  static address

  logical address

  block associative

  physical address

 11. A process is thrashing if:

  it is spending more time paging than executing

  it is spending less time paging than executing

   page fault occurs

   swapping cannot take place

 12. Fill in the blanks.
Virtual memory is normally implemented by ______________.

  all of the mentioned

  buses

  demand paging

  virtualization

 13. The use of virtual memory slows a computer because data must be mapped between virtual and physical memory, which requires extra hardware support for address translations.

  TRUE

  FALSE

 14. The first hard disks, created in the 1950s, could be up to 20 inches in diameter. Which company invented the hard disk?
vm4.jpg

  Xerox

  IBM

  HP

  Intel

 15. When purchasing a hard disk which of these is generally NOT a specification that would be of concern?

  data rate

  capacity

  mounting holes

  seek time