Which of the following is an example of a SPOOLED device?
Spool means simultaneous peri-pheral operations on line, a printer is a spooling device.
Concurrent processes are processes that
Concurrent processes are processes that share the CPU and memory. They do overlap in time while execution. At a time CPU entertain only one process but it can switch to other without completing it as a whole.
Which of the following are real-time systems?
1. An on-line railway reservation system ,
2. A process control system
3. Aircraft control system
4. Payroll processing system
Real-time system are very fast and quick respondents systems. Response time of such systems is very low, to the tune of 10 ms or 100 ms or even less.
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
In time-sharing operating system (example in Round-Robin), whenever the time slot given to a process expires, it goes back to READY state and if it requests for same I/O operation, then it goes to BLOCKED state.
Which of the following are single-user operating system?
MS-DOS (Microsoft Disk Operating System) is a single-user, single-tasking computer operating system that uses a command line interface. In spite of its very small size and relative simplicity, it is one of the most successful operating systems that has been developed to date.
In a multiprogramming environment
Multiprogramming environment means processor is executing multiple processes simultaneously by continuously switching between one-another. Therefore, multiple processes should reside in memory. However, processor can't executes more than one process at a time.
Suppose that a process is in ‘BLOCKED’ state waiting for some I/O service. When the service is completed, it goes to the
When process in blocked state waiting for some I/O services, whenever the services is completed it goes in the ready queue of the ready state.
Consider a set of 5 processes whose arrival time, CPU time needed and the priority are given below:
Note: Smaller the number, higher the priority.
If the CPU scheduling policy is FCFS, the average waiting time will be
Correct Answer :- a
Explanation : According to FCFS process solve are p1 p2 p3 p4 p5 so
for p1 waiting time =0 process time=10 then
for p2 waiting time = (process time of p1-arrival time of p2)=10-0=10 then
for p3 waiting time = (pr. time of (p1+p2)-arrival time of p3)=(10+5)-2=13 and
same for p4 waiting time=18-5=13
same for p5 waiting time=38-10=28
So total average waiting time = (0+10+13+13+28)/5
= 12.8
Consider a set of 5 processes whose arrival time, CPU time needed and the priority are given below:
Note: Smaller the number, higher the priority.
If the CPU scheduling policy is SJF, the average waiting time (without pre-emption) will be
Consider a set of 5 processes whose arrival time, CPU time needed and the priority are given below:
Note: Smaller the number, higher the priority.
If the CPU scheduling policy is SJF with preemption, the average waiting time will be
Doc | 23 Pages
Doc | 51 Pages
Doc | 4 Pages
Doc | 33 Pages
Test | 10 questions | 30 min
Test | 15 questions | 45 min
Test | 10 questions | 30 min
Test | 30 questions | 90 min
Test | 10 questions | 30 min