need all answers except the question 3 a

Q3 [4] a) Define the different items of scheduling and state information stored in the PCB. [2] b) Four batch jobs, J1 through J4, arrive at a computer center at essentially the same time. They have an estimated running time of 8, 12, 5 and 7 minutes, respectively. Their (externally defined) priorities are 3, 1, 2 and 4 respectively, with a lower value corresponding to a higher priority. Assuming priority scheduling, determine the turnaround time for each job and the average turnaround time for all jobs. Ignore process switching overhead. Q4 a) Determine whether following statements are True or False. Also justify your answer in at most [2] 3 lines:- 1. Using threads may result in minimization of context switching time. ii. The micro kernel architecture increases the portability of operating system code. b) Assume a disk with 200 tracks (numbered from 0 to 199) and that the disk request queue has random requests in it. The requested tracks, in the order received, are 53. 47, 39, 13, 90, 160, 140, 38 and 186. Starting at track 100, in the direction of increasing track number, Compute the number of tracks traversed and the average seek length using SCAN policy