A. Job queue
B. Pcb queue
C. Device queue
D. Ready queue
Explanation: PCB queue does not belong to queues for processes. PCB is a process control block which contains information related to process. Each process is represented by PCB.
A. It is placed in an i/o queue
B. It is placed in a waiting queue
C. It is placed in the ready queue
D. It is placed in the job queue
Explanation: When the process issues an I/O request it is placed in an I/O queue. I/O is a resource and it should be used effectively and every process should get access to it. There might be multiple processes which requested for I/O. Depending on scheduling algorithm I/O is allocated to any particular process and after completing I/O operation, I/O access is returned to the OS.
A. It is removed from all queues
B. It is removed from all, but the job queue
C. Its process control block is de-allocated
D. Its process control block is never de-allocated
Explanation: When a process terminates, it removes from all queues. All allocated resources to that particular process are deallocated and all those resources are returned back to OS.
A. It selects processes which have to be brought into the ready queue
B. It selects processes which have to be executed next and allocates cpu
C. It selects processes which heave to remove from memory by swapping
D. None of the mentioned
Explanation: A long-term scheduler selects processes which have to be brought into the ready queue. When processes enter the system, they are put in the job queue. Long-term scheduler selects processes from the job queue and puts them in the ready queue. It is also known as Job Scheduler.
A. Full, little
B. Full, lot
C. Empty, little
D. Empty, lot
Explanation: If all processes are I/O bound, the ready queue will almost empty and the short-term scheduler will have a little to do. I/O bound processes spend more time doing I/O than computation.
A. It selects which process has to be brought into the ready queue
B. It selects which process has to be executed next and allocates cpu
C. It selects which process to remove from memory by swapping
D. None of the mentioned
Explanation: A medium-term scheduler selects which process to remove from memory by swapping. The medium-term scheduler swapped out the process and later swapped in. Swapping helps to free up memory.
A. It selects which process has to be brought into the ready queue
B. It selects which process has to be executed next and allocates cpu
C. It selects which process to remove from memory by swapping
D. None of the mentioned
Explanation: A short-term scheduler selects a process which has to be executed next and allocates CPU. Short-term scheduler selects a process from the ready queue. It selects processes frequently.
A. The length of their queues
B. The type of processes they schedule
C. The frequency of their execution
D. None of the mentioned
Explanation: The primary distinction between the short-term scheduler and the long-term scheduler is the frequency of their execution. The short-term scheduler executes frequently while the long-term scheduler executes much less frequently.
A. Block
B. Wakeup
C. Dispatch
D. None of the mentioned
Explanation: The only state transition that is initiated by the user process itself is block. Whenever a user process initiates an I/O request it goes into block state unless and until the I/O request is not completed.
A. Blocked state
B. Ready state
C. Suspended state
D. Terminated state
Explanation: In a time-sharing operating system, when the time slot given to a process is completed, the process goes from the running state to the Ready State. In a time-sharing operating system unit time is defined for sharing CPU, it is called a time quantum or time slice. If a process takes less than 1 time quantum, then the process itself releases the CPU.