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Higher Study | Operating Systems | CPU Scheduling

Let processes are scheduled on a system using round robin scheduling; assume that there is only one process of r time units. Round robin time quantum is q time units and process switch time is s time units. If s < q < r, then process switch over head units are
What happen when an interrupt occurs in between CPU executing a program?
Let disk request come to a disk driver for cylinders in the order 10, 22, 20, 2, 40, 6 and 38, at the time when the disk driver is reading from cylinder 20. If the seek time is 6 ms per cylinder, then the total seek time for the disk arm scheduling time algorithm (FCFS - First Come First Serve) is:
Disk requests come to a disk driver for cylinders in the order 10, 22, 20, 2, 40, 6 and 38, at a time when the disk drive is reading from cylinder 20. The seek time is 6 ms/cylinder. The total seek time, if the disk arm scheduling algorithms is first-come-first-served is
A disk has tracks from 0 to 179. Currently the head is at track 40. The R/W requests for tracks are in the following order- 80, 102, 26, 160, 35, 10, 135. What is the total head movement when SSTF algorithm is used?
In this figure, 3 types of scheduling using preemptive scheduling policies is shown. Which of the following options is correctly referring to each of these scheduling types?
Consider the 3 processes, P1, P2 and P3 shown in the table. Process Arrival time Time unit Required P1 0 5 P2 1 7 P3 3 4   The completion order of the 3 processes under the policies FCFS and RR2 (round robin scheduling with CPU quantum of 2 time units) are
Suppose two jobs, each of which needs 10 min of CPU time, start simultaneously. Assume 50% I/O wait time. How long will it take for both to complete if they run sequentially ?
Consider a disk system having 60 cylinders. Disk requests are received by a disk drive for cylinders 10, 22, 20, 2, 40, 6, and 38, in that order. Assuming the disk head is currently at cylinder 20, what is the time taken to satisfy all the requests if it takes 2 milliseconds to move from one cylinder to an adjacent one and Shortest Seek Time First (SSTF) algorithm is used ?
An operating system uses shortest remaining time (SRT) scheduling algorithm. Consider the arrival times and execution time for the following processes: Proces Arrival Time Execution Time P1 0 20 P2 15 25 P3 30 10 P4 45 15 What is total waiting time for process P2?
Three CPU-bound tasks, with execution times of 15, 12 and 5 time units respectively arrive at times 0, t and 8, respectively. If the operating system implements a shortest remaining time first scheduling algorithm, what should be the value of t to have 4 context switches? Ignore the context switches at time 0 and at the end.
Consider a disk system with 100 cylinders. The request to access the cylinders occur in the following sequences 4, 37, 10, 7, 19, 73, 2, 15, 6, 20 Assuming the head is currently at cylinder 50, what is the time taken to satisfy all requests if it takes 1 ms to move from one cylinder to adjacent one and shortest seek time first algorithm is used
Consider a disk sequence with 100 cylinders. The request to access the cylinder occur in the following sequence : 4, 34, 10, 7, 19, 73, 2, 15, 6, 20 Assuming that the head is currently at cylinder 50, what is the time taken to satisfy all requests if it takes 2 ms to move from one cylinder to adjacent one and shortest seek time first policy is
Consider four processes P, Q, R, and S scheduled on a CPU as per round-robin algorithm with a time quantum of 4 units. The processes arrive in the order P, Q, R, S, all at time t = 0. There is exactly one context switch from S to Q, exactly one context switch from R to Q, and exactly two context switches from Q to R. There is no context switch from S to P. Switching to a ready process after the termination of another process is also considered a context switch. Which one of the following is NOT possible as CPU burst time (in time units) of these processes?  
Which of the following criteria(n) is/are being used to compare the CPU scheduling algorithms? A. Throughput B. CPU utilization C. Waiting time D. Response time
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