Quiznetik

Embedded Real Time Operating System | Set 2

1. Preemptive, priority based scheduling guarantees ____________

Correct : B. soft real time functionality

2. What is Event latency?

Correct : D. the amount of time that elapses from when an event occurs to when it is serviced.

3. Real time systems need to __________ the interrupt latency.

Correct : A. minimize

4. The amount of time required for the scheduling dispatcher to stop one process and start another is known as ______________

Correct : C. dispatch latency

5. The most effective technique to keep dispatch latency low is to ____________

Correct : B. provide preemptive kernels

6. Antilock brake systems, flight management systems, pacemakers are examples of

Correct : D. safety critical system and hard real time system

7. In real time operating system ____________

Correct : B. a task must be serviced by its deadline period

8. In a real time system the computer results ____________

Correct : A. must be produced within a specific deadline period

9. . If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.B will have ______ percent of the total processor time.

Correct : B. 15

10. Earliest deadline first algorithm assigns priorities according to ____________

Correct : B. deadlines

11. A process P1 has a period of 50 and a CPU burst of t1 = 25, P2 has a period of 80 and a CPU burst of 35. The total CPU utilization is ____________

Correct : C. 0.94

12. A process P1 has a period of 50 and a CPU burst of t1 = 25, P2 has a period of 80 and a CPU burst of 35., the priorities of P1 and P2 are?

Correct : B. keep varying from time to time

13. A process P1 has a period of 50 and a CPU burst of t1 = 25, P2 has a period of 80 and a CPU burst of 35., can the two processes be scheduled using the EDF algorithm without missing their respective deadlines?

Correct : A. Yes

14. Using EDF algorithm practically, it is impossible to achieve 100 percent utilization due to __________

Correct : A. the cost of context switching

15. If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.A will have ______ percent of the total processor time.

Correct : C. 50

16. If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.C will have ______ percent of the total processor time.

Correct : A. 20

17. If there are a total of T = 100 shares to be divided among three processes, A, B and C. A is assigned 50 shares, B is assigned 15 shares and C is assigned 20 shares.If a new process D requested 30 shares, the admission controller would __________

Correct : B. deny entry to D in the system

18. In a safety critical system, incorrect operation ____________

Correct : C. causes major and serious problems

19. The amount of memory in a real time system is generally ____________

Correct : A. less compared to PCs

20. What is the priority of a real time task?

Correct : B. must not degrade over time

21. Memory management units ____________

Correct : D. all of the mentioned

22. A process P1 has a period of 50 and a CPU burst of t1 = 25, P2 has a period of 80 and a CPU burst of 35. Can the processes be scheduled without missing the deadlines?

Correct : B. No

23. Type of processor in which single task of a particular application is process is termed as Select one:

Correct : B. dedicated processor

24. Calculate the idle time of the processor with 3 periodic tasks whose execution times are given as 1, 1, and 3, and their periods are 3, 4, and 10. Select one: 17% 12% 88%

Correct : B. 0.12

25. In rate monotonic scheduling algorithm Select one:

Correct : B. longer duration job has higher priority

26. Tasks whose execution would begin randomly and within the interval of arrival times of consecutive tasks is known as

Correct : C. Sporadic Task

27. What is True for a task vis-à-vis a process?

Correct : B. Tasks represent only a single sequence of instructions

28. What does the utilization rate tells us? Select one:

Correct : A. If it is larger or equal to 1, the system is not feasible

29. if jobs have unpredictable release times, a task is termed :

Correct : A. aperiodic

30. What is TRUE for an aperiodic task and a sporadic task:

Correct : C. A sporadic task occurs randomly and has hard real time requirements

31. State whether the following statements are True or False for the features of real time operating system. i) fast process or thread switch ii) ability to respond to external interrupts quickly. iii) minimization of intervals during which interrupts are enabled. iv) preemptive scheduling based on priority

Correct : C. i, ii and iv only

32. Effective release time of a job without the predecessors is equal to its given …………….

Correct : A. release time

33. Effective release time of a job with predecessors is equal to the maximum value among, its…………and…………..

Correct : B. release time and effective release time of all of the predecessors.

34. Effective deadline of job without the successor is equal to its given ……………

Correct : B. Deadline

35. Effective deadline of job with successor is equal tothe minimum value among its deadlines and …………………………

Correct : C. deadlines of all the successors

36. LRT schedules all the job backward from …………………... of all the job in priority driven manner to the current time.

Correct : B. latest deadline

37. In on-line scheduling, scheduler make the schedule ……………………... that will be released in future.

Correct : B. without the knowledge of the jobs

38. In which scheduling certain amount of CPU time is allocated to each process ?

Correct : B. roportional share scheduling

39. Scheduling of tasks is a very important consideration in RTOS. Which of the following best described the scheduling policy design:

Correct : D. The scheduler must not use pre-emptive policy option, but must employ priority consideration.