In what scenario is virtual memory most crucial?

Virtual memory is most crucial when running multiple applications that exceed the RAM capacity. This scenario typically occurs in computing environments where the demand for memory surpasses the available physical memory (RAM). Virtual memory allows the operating system to use a portion of the hard disk as an extension of RAM, enabling the system to manage larger workloads by storing parts of inactive processes on the disk, thereby freeing up RAM for active processes.

By allowing memory pages to be swapped between physical memory and disk storage, virtual memory helps maintain system performance and allows applications to run smoothly even when total memory requirements exceed what is physically available. This functionality is essential for multitasking environments where several applications may be concurrently active and may require more memory than the system can provide in physical RAM alone.

In contrast, the other scenarios mentioned are not situations where virtual memory is as critical. Having excess physical memory available would reduce the need for virtual memory, and using low-powered devices or performing maintenance tasks does not inherently demand extensive memory management.