BARC 2020 CS Question paper analysis

BARC recently conducted their online exam for OCES/DGFS for all the eligible disciplines. Many of the candidates appearing for BARC exam are curious about the syllabus. If you visit official website of BARC they have not mentioned any concrete syllabus. Unlike GATE, they don't even release their previous year question papers. This is what they have mentioned about the syllabus and question paper on their website. https://www.barconlineexam.in/engineer/info-about-online-exam.html

If you surf on internet to check the syllabus of BARC exam, many of the third party websites mention that syllabus of BARC is same as GATE syllabus.So I recently appeared in BARC online exam 2020 in Computer Science discipline and what i found is, of course the syllabus of BARC is same as gate syllabus but there were questions from the other subjects as well which are not in GATE syllabus. Like there were questions from OOPS, Java programming language, Computer vision, Machine learning, Deep learning etc.

Also many candidates speculate about the number of questions asked from mathematics domain as the syllabus for maths is vast. So this post is all about to make you familiar about the syllabus, the type of questions being asked and their difficulty level based on my exam experience. I have also listed the topic wise questions which i remember which were asked in this year's exam.

As far as the difficulty level of questions is considered, 80% questions had the similar level of difficulty as one mark questions being asked in GATE. While this was the case for all disciplines as per the feedback which i received from my friends of other disciplines. Most of the questions were straight forward while some were repeated or very similar (only data being changed) from previous year GATE questions. Here are the topic wise question which i remember.

Mathematics 

It is usually seen that there are only a few questions being asked in maths as contrary to the vast syllabus. There were  only about  4-5 questions from mathematics that too were mainly from discrete mathematics.

1.  Probability: Given 15 bulbs in which only 5 are defective, find the probability to pick 6 bulbs such that only one of them is defective.  Hint:  C(5,1)*C(10,5)/C(15,6) 
2.  Given  a closure S, following a*(b*c) = (a*b)*c. S can be a?  a. group b. lattice c. monoid  d. semi group.   Hint( since S follows associative property so it is a semigroup)
3. A relation was given and was asked to check whether it was equivalent and partially ordered relation or not. 
4. One question to find laplace transform ( easy though formula based)
5. Linear algebra: Given two 2*2 matrix A and B satisfying equation Ax=B and asked to find matrix x.

Machine learning and deep learning

1. Which of the following is not an ensemble algorithm ?  a. random forest  b. bagging  c.boosting  d. decision tree  Hint (decision tree)
2. Given a passage and a paragraph text, which of the following is best suited to find whether that  text exists in the given passage or not. a.  CNN  b.  LSTM  c. RNN  d. Neural network.

Computer vision

1. Which of the following technique is used to remove edges between two touching image?          a. dilation b.  erosion  c.  closing d.  opening.
2. Which of the following filter are used for filtering impulsive noise, 4 filters were given as option, well correct answer was median filter.    

OOPS

Two questions were there from this topic.

1. Which of the following reduces the number of function used in sub classes for implementation of same functionality ? a. polymorphism  b. data binding  c. inheritance  d. abstraction.
2. Which of the following operators can be overloaded?  a.  member access operator b. conditional operator c. delete operator d. scope resolution operator. Hint (delete operator)

Java programming

Two output based questions were asked. Code snippet were given involving inheritance, derived and base class having same function name and we have to resolve run time binding of functions and answer the output. Refer this link for example https://www.geeksforgeeks.org/static-vs-dynamic-binding-in-java/

Operating system (OS)

A lot of questions were asked from OS, i guess it has the largest weightage among all other subjects. All of the questions were straight forward, with medium to easy difficulty. 

1. A CPU scheduling question on preemptive SJF to find average Turnaround time.
2. Question on disk scheduling algorithm: Cylinder numbers were given and using scan algorithm, find number of head movements.
3. A question similar to this, only value being changed https://www.geeksforgeeks.org/gate-gate-cs-2009-question-51/
4. Similar to this https://www.geeksforgeeks.org/gate-gate-cs-2004-question-49/
5. Given a reference string and 4 frames, find no. of page faults using LFU policy.
6. Given page fault service time and memory access time also the probability of page fault find effective memory access time.
7. Standard semaphore question, given n concurrent processes a shared resource and a binary semaphore initialized to 1. A code having critical section, wait and signal operations and asked above processes leads to? a. deadlock  b. starvation but not deadlock  c. violation of mutual exclusion  d. none
8. Question on finding safe state, given 3 processes, total instance of each resource, current allocation and max requirement vector for each process. An execution sequence <p3,p2,p1> was given and asked whether execution will lead to safe state or not. Hint( find need matrix and proceed)
9. Given a 2 dimensional array of size 1024*1024, row major and column major accesses of array were given and LRU page replacement policy being used, which access method will have more number of page faults. Similar to this https://stackoverflow.com/questions/15961582/calculating-number-of-page-faults-for-2-d-array

Compter Architecture

All the questions were simple and straight. They didn't touch any advance concepts like pipelining, DMA (cycle stealing and burst mode), operand forwarding etc.

1. Given 64 registers and 32 data lines what would be size of RAM.
2. Statements given and asked which one is true. i.) LRU can be used for page replacement in direct mapping.  ii) FIFO can be used for page replacement in fully associative mapping.
3. Given cache access time, memory access time, and hit ratio. Find effective memory access time.
4. Question from micro programmed control unit, a control signal to design using both vertical and horizontal microgramming. Question was somewhat like this: We have 4 control signals which are all required simultaneously and 32 signals which are required one at a time. What is the minimum no. of bits required in control field to implement this. Hint (we will implement 4 signals using horizontal and other 32 signals using a (5*32) decoder using vertical approach)

Data structure and Algorithm

1. Given a level order traversal of min heap as 3,5,11,9,7 how many different min heaps are possible using given data.
2. Given a level order traversal of min heap, further two more elements are being added and we needed to find the resulting level order ( obviously some swapping will happen because of heapify function in order to maintain min heap property)
3. Recursive equations of binary search, quick sort, merge sort and tower of hanoi were given in a column asked to match their corresponding entries.
4. Given state of an array which is sorted to some intermediate step 5,3,6,8,18,15 (not fully sorted). Which of the following sorting algorithm is being applied?. a. merge sort  b. insertion sort c. quick sort d. selection sort. Hint (quick sort)
5. Given a preorder traversal of a binary tree as 3,5,7,6,8 how many unique binary tree can we have?
6. Time complexity of following code: Hint (its a memoized code of for finding fibonacci series, O(n^2))

           int fun(int n) {

                    if (n<2)

                             return 1;

                             if (fib[n]!=0)

                                      return fib[n];

                                                     fib[n] = fun(n-1)+fun(n-2);

                                return fib[n];

        }

Digital electronics

1. Given a 4*4 kmap what would be its reduced expression?
2. Given a reduced expression and four( 4* 4) kmaps in options, which one of the kmap is the representation of reduced expression?
3. Given an asynchronous counter having three D flip flops and the counter initially counts 0 after how many cycle it will count 0 again?
4. How many number of 1's present in the decimal equivalent of  9*1024+11*512+6*256?
5. How many number of 0's are present in the 2's complement representation of  -1136?
6. Given two binary numbers a=101011, b=111111, and two expressions i.) (a|b)&(a&b)            ii.) (a|b)|(a&b). Which one is true? a. i) is greater  b. ii) is greater  c. both are equal d. value of expression  i) is zero.

C programming

1. An output based question: A function calling another function which is calling itself recursively.Similar to the question asked in GATE this year. Instead of asking final return value they included printf statement in between and asked what would be printed?
   
2. A complex declaration was given like int (*(*f() ) [ ]) ( ) what does this declaration mean? Hint ( f is a function which return a pointer to an array of pointer to function returning an int)

Theory of computation(TOC)

Most of the questions were simple and seen before. Majority of the questions were from DFA and regular expressions. There were not any questions from decidability and undecidability, countability, turing machines, recursive languages etc.

1. Given some  languages and asked which are regular and context free (all were standard languages which you might have seen before).
2. Minimum number of states in NFA and DFA respectively accepting a language having strings lengths either divisible by 3 or 5
3. Given a DFA find its regular expression.
4. Given a regular expression, which of the following DFA accepts it. (four DFA's were given in the option)

Computer Networks (CN)

About 5-6 questions were from this topic. However i remember only few.

1. Given a subnet mask 172.16.24.8/21 , find how many number of hosts are present in a network?
2. Given distance between stations, velocity and length of packet at what bandwidth Tp=Tt?(propagation time = transmission time) Hint ( d/v = l/b)
3. A numerical on distance routing protocol.

Database Management System (DBMS)

Four questions were there from this subject all were of easy level.

1. Question on SQL query : Two tables having referential integrity were given and a query was given followed by four options
2. ER model to relational db conversion: Given two entities and two relations (having no attribute). One of the relation is one to many another is many to many. Minimum number of relations required to convert this ER diagram to relational DB? Hint (3, two for entities and one for many to many relation)
3. Given a relation abcde and functional dependencies a-->b, a-->c, d-->e. If we decompose given relation using BCNF which of the following decompositions won't result? a.) abc  b.) de     c.) cde d.) none Hint (de, because if we decompose it in only abc and de then that decomposition will be lossy).
4. Given a relation having only single valued attributes in which of following the normal form it can be?     a. 2nf b. 1nf c. 3nf  d. bcnf . Hint(1nf).

Compiler Design (CD)

There was only one question from this subject, that too the first one in my paper.

1. Given grammar E--> E+T and E-->T,  which of the following parser won't be able to parse the given grammar. a. LR(1)  b. LALR  c. CLR d. none.  (LL(1) was not given in the option, otherwise this question would have been a cake walk as left recursion is there in the grammar).

Software Engineering (SE)

Two questions were there from SE both numerical type some graph was given. Don't remember the questions.

Information and Network Security (INS)

Only one question was there that too the famous one which you might have seen previously in many exams and mock tests.

1. Digital certificate : A sender signs digital certificate and encrypts it using his private key. It would be decrypted by senders site using? Hint ( Sender will decrypt using public key of sender).