GATE CS 2001 Q1.8 — Memory Management and Virtual Memory

Let's analyze each statement to identify the false one:

• Statement A: "Virtual memory implements the translation of a program's address space into physical memory address space" — True. The Memory Management Unit (MMU) uses page tables to map virtual (logical) addresses generated by the CPU to physical addresses in RAM.
• Statement B: "Virtual memory allows each program to exceed the size of the primary memory" — True. Virtual memory allows a process to execute even if only a portion of its address space is loaded into physical memory. The rest resides on secondary storage (swap space).
• Statement C: "Virtual memory increases the degree of multiprogramming" — True. Since only parts of a process need to be in physical memory at any given time, more processes can be partially loaded into RAM simultaneously, increasing the degree of multiprogramming.
• Statement D: "Virtual memory reduces the context switching overhead" — False. Virtual memory increases context switching overhead. During a context switch, the OS must update memory management structures (like the page table base register) and flush or invalidate the Translation Lookaside Buffer (TLB). Additionally, handling page faults requires disk I/O, which adds significant overhead.

Therefore, statement D is false.