Welcome to Operating System Quiz, Advanced Level !!

Question 1. Consider a machine with 64 MB physical memory and a 32-bit virtual address space. If the page size is 4KB, what is the approximate size of the page table?

16 MB

8 MB

2 MB

24 MB

Question 2. The degree of Multiprogramming is controlled by

CPU Scheduler

Context Switching

Long-term Scheduler

Medium term Scheduler

Question 3. Demand paged memory allocation

allows the virtual address space to be independent of the physical memory

allows the virtual address space to be a multiple of the physical memory size

allows deadlock to be detected in paging schemes

is present only in Windows NT

Question 4. _________ allocates the largest hole (free fragment) available in the memory.

best fit

worst fit

first fit

none of the above

Question 5. Consider Peterson?s algorithm for mutual exclusion between two concurrent processes i and j. The program executed by process is shown below
      repeat
          flag [i] = true;
          turn = j;
          while ( P ) do no-op;
          Enter critical section, perform actions, then exit critical section
      flag [ i ] = false;
      Perform other non-critical section actions
     until false;

For the program to guarantee mutual exclusion, the predicate P in the while loop should be

flag [j] = true and turn = i

flag [j] = true and turn = j

flag [i] = true and turn = j

flag [i] = true and turn = i

Question 6. If all page frames are initially empty, and a process is allocated 3 page frames in real memory and references its pages in the order 1 2 3 2 4 5 2 3 2 4 1 and the page replacement is FIFO, the total number of page faults caused by the process will be ?

10

7

8

9

Question 7. _________ page replacement alogorithm suffers from Belady's anamoly.

LRU

MRU

FIFO

LIFO

Question 8. An optimal scheduling algorithm in terms of minimizing the average waiting time of a given set of processes is

FCFS scheduling algorithm

Round robin scheduling algorithm

Shorest job - first scheduling algorithm

None of the above

Question 9. Using Priority Scheduling algorithm, find the average waiting time for the following set of processes given with their priorities in the order: Process : Burst Time : Priority respectively . P1 : 10 : 3 , P2 : 1 : 1 , P3 : 2 : 4 , P4 : 1 : 5 , P5 : 5 : 2.

8 milliseconds

8.2 milliseconds

7.75 milliseconds

3 milliseconds

Question 10. _________ is a high speed cache used to hold recently referenced page table entries a part of paged virtual memory

Translation Lookaside buffer

Inverse page table

Segmented page table

all of the above