Paging is implemented in ........

Explanation:

Answer : b.  Hardware

Paging is a memory management scheme that eliminates the need for contiguous allocation of physical memory. This scheme permits the physical address space of a process to be non – contiguous.

• Logical Address or Virtual Address (represented in bits): An address generated by the CPU
• Logical Address Space or Virtual Address Space( represented in words or bytes): The set of all logical addresses generated by a program
• Physical Address (represented in bits): An address actually available on memory unit
• Physical Address Space (represented in words or bytes): The set of all physical addresses corresponding to the logical addresses

Example:

• If Logical Address = 31 bit, then Logical Address Space = 231 words = 2 G words (1 G = 230)
• If Logical Address Space = 128 M words = 27 * 220 words, then Logical Address = log2 227 = 27 bits
• If Physical Address = 22 bit, then Physical Address Space = 222 words = 4 M words (1 M = 220)
• If Physical Address Space = 16 M words = 24 * 220 words, then Physical Address = log2 224 = 24 bits

The mapping from virtual to physical address is done by the memory management unit (MMU) which is a hardware device and this mapping is known as paging technique.