[amp_mcq option1=”simple to implement” option2=”used in all major commercial operating systems” option3=”less efficient in utilization of memory” option4=”useful when fast I/O devices are not available E. None of the above” correct=”option2″]
The correct answer is: B. used in all major commercial operating systems.
Virtual memory is a technique that allows a computer to run programs that require more memory than is physically available in the computer’s memory. It does this by creating a virtual address space for each program, which is a larger address space than the physical memory available. The virtual address space is divided into pages, and each page can be mapped to a physical page in memory or to a page on disk. When a program tries to access a page that is not in memory, the operating system will page the page in from disk.
Virtual memory is used in all major commercial operating systems, including Windows, macOS, and Linux. It is also used in some embedded systems.
The other options are incorrect:
- A. Virtual memory is not simple to implement. It requires a complex operating system to manage the virtual address space and the paging of pages in and out of memory.
- C. Virtual memory can be more efficient in utilization of memory than a system without virtual memory. This is because virtual memory allows programs to share memory pages, and it also allows the operating system to page out unused pages to disk.
- D. Virtual memory is not useful when fast I/O devices are not available. In fact, virtual memory can actually make I/O slower, because the operating system has to page in pages from disk when a program needs them.
- E. None of the above is correct.