Questions

The answer is 'X'.

1. It is the 24th letter in the alphabetical order.

2. XX (20 in Roman)

3. XXX is used to refer dirty.

Fragmentation occurs in a dynamic memory allocation system when many of the free blocks are too small to satisfy any request. 

External Fragmentation: External Fragmentation happens when a dynamic memory allocation algorithm allocates some memory and a small piece is left over that cannot be effectively used. If too much external fragmentation occurs, the amount of usable memory is drastically reduced. Total memory space exists to satisfy a request, but it is not contiguous. 

Internal Fragmentation: Internal fragmentation is the space wasted inside of allocated memory blocks because of restriction on the allowed sizes of allocated blocks. Allocated memory may be slightly larger than requested memory; this size difference is memory internal to a partition, but not being used

8085 is a one address microprocessor. In 8085 interrupts  are classified by software and hardware interrupts.