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BARC 2020: Mini Mock 3 (App update required to attempt this test)

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Question 1

Consider a machine with 256 MB virtual address space and 512 MB physical address space. If page table entry is of 4B, then what should be minimum page size?

Question 2

Consider the following 3 processes with 3 binary semaphores with initial values

What will be the correct pattern generated by these 3 processes, write it without any space between the digit?

Question 3

Among the following CPU scheduling algorithms , how many suffers from starvation : _____________




* Longest Job First

* Pre-emptive Priority

* Round Robin

* Multi-level Feedback Queue Scheduling

Question 4

In paging system, page replacement policies are used to replace the pages from main memory whenever needed. Consider a system with 4 page main memory. The following table represent the page no, time at which page is loaded to the main memory and time at which the page was last referred:

Which pages will be replaced by using FIFO and LRU scheme respectively?

Question 5

Consider the following cylinder request of disk coming in the given order:
10, 22, 20, 2, 40, 6, 38
Assume the disk head is currently positioned at cylinder 20. Seek time takes 6 ms. How many number of cylinder moves are taken for the given requests using the SCAN scheduling? (Assume initially head is moving upward)

Question 6

Consider the below concurrent program

Int x= 0, y= 0;



X=1;. //A

Y= Y +X.    //B



Y= 4;.     // C

X= X +5.      //D



What is the final value of x and y after computing the concurrent program.

1.  X=1     Y=5

2.X=  6     Y=10

3.X= 6       Y=5

4.X=1       Y=4

Question 7

Consider the following four processes with arrival times (in milliseconds) and their length of CPU bursts (in milliseconds) as shown below:


These processes are run on a single processor using a preemptive Shortest Remaining Time First scheduling algorithm. If the average waiting time of the processes is 1 millisecond, then the value of Z is________.

Question 8

Assume that the following jobs are to be executed on a single processor system:

What is the average waiting time using the scheduling technique Highest Response Ratio Next?

Question 9

What is the return value of child process when the fork is executed in parent process?

Question 10

What is the proper sequence of these activities taking place in a system?

1) Deadlock Avoidance

2) Deadlock Prevention

3) Deadlock Detection and Recovery

4) Deadlock Ignorance

Write the numbers in a proper order. For example, if you think that the sequence is 1234 then type the numbers in the same sequence i.e. 1234.

Question 11

Consider the following problems:

A) L is a context-sensitive language (CSL), the complement of L is of the same type.

B) Let L1 and L2 be CSL, the intersection of L1 and L2 is empty or not.

C) Finiteness problem in CFGs.

D) Emptiness problem for CFGs

The number of problems that are decidable is ____.

Question 12

which of the following grammar represent all the strings which can be generate by language L = {aibjck / i!=j and j!=k}

Question 13

Which of the following is denoted by 2∑*?

Question 14

Consider a Language L1 which is Regular and L2 which is DCFL. We perform the following operations on these languages.

L3 = L1 U L2

L4 = L3’

L5 = L4 L1

L6 = L5 – L1

L6 = L5*

L7 = L6 U L2

L8 = L7 U L1

The resultant language we get in L8 is?

Question 15

Which of the following option is correct?

Question 16

Consider the following ε-NFA

The number of final states in DFA is?

Question 17

Give the R.E described by the following NFA .

Question 18

The maximum number of suffixes of ‘n’ length string is?

Question 19

Consider the transition table below:

What will be  ?

Question 20

How many of the following statements are true?

1) The intersection of two regular languages is infinite is decidable.

2) Whether a given context free language is regular is decidable.

3) Whether a given grammar is context free grammar is not decidable.

4) Finiteness problem of regular language is decidable.

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