Operating Systems Questions

16) The following table shows a system in a safe state. The system has a total of 12 tape drives. Job Allocated Max Need 4 Select which of the following would change it to an unsafe state: 16.1.job 2 requests and is allocated 2 tape drives 16.2. job 1 requests and is allocated 2 tape drives 16.3. job 3 requests and is allocated 2 tape drives 17) Which of the problems listed below is related to Re-locatable Dynamic Partition m allocation scheme 17.1 internal fragmentations; 17.2 external fragmentations; 17.3 compaction overhead; 17.4 large numbers of tables; 17.5 large numbers of interrupts. S) Demand aing Memory Allocation allows Memory Manager to solve problems of 18.1 internal fragmentation; 18.2 keeping large tables in the memory; 18.3 having job size limited to physical memory size; 18.4 eliminating overhead for handling necessary paging hardware; 18.5 eliminating possibility of thrashing 19) If the Modified Bit in the Page Map Table equal to 1, it means 19.1 the page must be modified; 19.2 the page cannot be modified; 19.3 the page must be saved before removing it from the memory; 19.4 an address of the page must be modified; 19.5 the page may be relocated in the memory 20) The main disadvantage of Fist-Come First-Serve process scheduling algorithm is: 20.1 the rank of turnaround time varies widely; 20.2 the turnaround time is always very big; 20.3 the waiting time is always very big; 20.4 the algorithm is very complex in implementation; 20.5 the algorithm can be used only for short jobs