These are operating systems problem. Please provide answer typed out.

8. Explain how the context switch is performed using these keywords: (a) PCB, (b) program counter, (c) ready queue, and (d) memory. Note that your answer should include all keywords to get credits. (10pts) 9. Assume that a circular array with 5 elements is created to solve the producer-consumer problem. The circular array is initially empty. Draw the empty circular array with the in and out pointers (represented as arrows) as I illustrated in class (5pts). Now assume that two items 'A'|| and 'B' have been added to the circular array. Draw the circular array with the in and out pointers after these items have been added (5pts)