Which of the following addressing modes are suitable for program relocation at run time?
$$1.$$ Absolute addressing
$$2.$$ Based addressing
$$3.$$ Relative addressing
$$4.$$ Indirect addressing

The minimum number of page frames that must be allocated to a running process in a virtual memory environment is determined by.

Consider a System with a two-level paging scheme in which a regular memory access takes $$150$$ nanoseconds, and servicing a page fault takes $$8$$ milliseconds. An average instruction takes $$100$$ nanoseconds of $$CPU$$ time, and two memory accesses. The $$TLB$$ hit ratio is $$90$$% and the page fault rate is one in every $$10,000$$ instructions. What is the effective average instruction execution time?

Consider an operating system capable of loading and executing a single sequential user process at a time. The disk head scheduling algorithm used is First Come First Served $$(FCFS).$$ If $$FCFS$$ is replaced by Shortest Seek Time First $$(SSTF),$$ claimed by the vendor to give $$50\% $$ better benchmark results, what is the expected improvement in the $${\rm I}/O$$ performance of user programs?