GATE 2020 CS – Previous Year Questions with Solutions
All 65 questions of GATE 2020 CS with answers and explanations. Read each question, then practise it by topic or as a full paper.
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- Question 1 – Raman is confident of speaking English six months as he has been practising regularly the last three weeks.
- Question 2 – His knowledge of the subject was excellent but his classroom performance was .
- Question 3 – Select the word that fits the analogy: Cook : Cook :: Fly :
- Question 4 – The dawn of the 21st century witnessed the melting glaciers oscillating between giving too much and too little to billions of people who depend on…
- Question 5 – There are multiple routes to reach from node 1 to node 2, as shown in the network. [Figure: edge costs 1→a 200, 1→b 300, 1→f 100, a→c 100, a→2 200,…
- Question 6 – Goods and Services Tax (GST) is an indirect tax introduced in India in 2017 that is imposed on the supply of goods and services, and it subsumes all…
- Question 7 – If P = 3, R = 27, T = 243, then Q + S = .
- Question 8 – The figure below shows an annular ring with outer and inner radii as b and a, respectively. The annular space has been painted in the form of blue…
- Question 9 – Two straight lines are drawn perpendicular to each other in X-Y plane. If and are the acute angles the straight lines make with the X-axis, then + is…
- Question 10 – The total revenue of a company during 2014-2018 is shown in the bar graph. If the total expenditure of the company in each year is 500 million rupees,…
- Question 11 – Consider the functions I. e-x II. x2- x III. x3+1 Which of the above functions is/are increasing everywhere in [0,1]?
- Question 12 – For parameters a and b, both of which are (1), T(n)=T(n1/a)+1, and T(b)=1. Then T(n) is
- Question 13 – Consider the following statements. I. Daisy chaining is used to assign priorities in attending interrupts. II. When a device raises a vectored…
- Question 14 – Consider the following data path diagram. [Figure: single-bus data path with MAR, MDR, IR, PC, register file R0-R7, TEMP1, TEMP2 and ALU] Consider an…
- Question 15 – The preorder traversal of a binary search tree is 15, 10, 12, 11, 20, 18, 16, 19. Which one of the following is the postorder traversal of the tree?
- Question 16 – What is the worst case time complexity of inserting n2 elements into an AVL-tree with n elements initially?
- Question 17 – Which one of the following regular expressions represents the set of all binary strings with an odd number of 1's?
- Question 18 – Consider the following statements. I. If L 1 L 2 is regular, then both L 1 and L 2 must be regular. II. The class of regular languages is closed under…
- Question 19 – Consider the following statements. I. Symbol table is accessed only during lexical analysis and syntax analysis. II. Compilers for programming…
- Question 20 – Consider the language L=\an n 0\\anbn n 0\ and the following statements. I. L is deterministic context-free. II. L is context-free but not…
- Question 21 – Consider allocation of memory to a new process. Assume that none of the existing holes in the memory will exactly fit the process's memory…
- Question 22 – Consider the following statements about process state transitions for a system using preemptive scheduling. I. A running process can move to ready…
- Question 23 – Consider a relational database containing the following schemas. Catalogue(sno, pno, cost): (S1,P1,150), (S1,P2,50), (S1,P3,100), (S2,P4,200),…
- Question 24 – Which one of the following is used to represent the supporting many-one relationships of a weak entity set in an entity-relationship diagram?
- Question 25 – Consider the following statements about the functionality of an IP based router. I. A router does not modify the IP packets during forwarding. II. It…
- Question 26 – What is the worst case time complexity of inserting n elements into an empty linked list, if the linked list needs to be maintained in sorted order?
- Question 27 – Let R be the set of all binary relations on the set \1,2,3\. Suppose a relation is chosen from R at random. The probability that the chosen relation…
- Question 28 – Let G be a group of 35 elements. Then the largest possible size of a subgroup of G other than G itself is .
- Question 29 – A multiplexer is placed between a group of 32 registers and an accumulator to regulate data movement such that at any given point in time the content…
- Question 30 – If there are m input lines and n output lines for a decoder that is used to uniquely address a byte addressable 1 KB RAM, then the minimum value of…
- Question 31 – A direct mapped cache memory of 1 MB has a block size of 256 bytes. The cache has an access time of 3 ns and a hit rate of 94%. During a cache miss,…
- Question 32 – Consider the following C program. The output of the program is .
- Question 33 – Consider a double hashing scheme in which the primary hash function is h 1(k)=k 23, and the secondary hash function is h 2(k)=1+(k 19). Assume that…
- Question 34 – Consider the following grammar. S aSB d B b The number of reduction steps taken by a bottom-up parser while accepting the string aaadbbb is .
- Question 35 – Assume that you have made a request for a web page through your web browser to a web server. Initially the browser cache is empty. Further, the…
- Question 36 – Which of the following languages are undecidable? Note that M indicates encoding of the Turing machine M. L 1=\ M L(M)=\ L 2=\ M,w,q M on input w…
- Question 37 – Let A and B be two n n matrices over real numbers. Let rank(M) and (M) denote the rank and determinant of a matrix M, respectively. Consider the…
- Question 38 – Consider the Boolean function z(a,b,c). [Figure: z is the output of an OR gate whose inputs are a and the output of an AND gate with inputs b (b…
- Question 39 – Consider three registers R1, R2, and R3 that store numbers in IEEE-754 single precision floating point format. Assume that R1 and R2 contain the…
- Question 40 – A computer system with a word length of 32 bits has a 16 MB byte-addressable main memory and a 64 KB, 4-way set associative cache memory with a block…
- Question 41 – Let G=(V,E) be a weighted undirected graph and let T be a Minimum Spanning Tree (MST) of G maintained using adjacency lists. Suppose a new weighted…
- Question 42 – Consider the following languages. L 1=\wxyx w,x,y(0+1)+\ L 2=\xy x,y(a+b)*, x = y , x y\ Which one of the following is TRUE?
- Question 43 – Consider the productions A → PQ and A → XY. Each of the five non-terminals A, P, Q, X, and Y has two attributes: s is a synthesized attribute, and i…
- Question 44 – Each of a set of n processes executes the following code using two semaphores a and b initialized to 1 and 0, respectively. Assume that count is a…
- Question 45 – Consider the following five disk access requests of the form (request id, cylinder number) that are present in the disk scheduler queue at a given…
- Question 46 – Consider a relational table R that is in 3NF, but not in BCNF. Which one of the following statements is TRUE?
- Question 47 – Consider a schedule of transactions T 1 and T 2. In time order (RX = Read(X), WX = Write(X)): T1:RA, T2:RB, T2:WB, T1:RC, T2:RD, T1:WD, T2:WC, T1:WB,…
- Question 48 – An organization requires a range of IP addresses to assign one to each of its 1500 computers. The organization has approached an Internet Service…
- Question 49 – Which one of the following predicate formulae is NOT logically valid? Note that W is a predicate formula without any free occurrence of x.
- Question 50 – Let G=(V,E) be a directed, weighted graph with weight function w:ER. For some function f:VR, for each edge (u,v) E, define w'(u,v) as…
- Question 51 – In a balanced binary search tree with n elements, what is the worst case time complexity of reporting all elements in range [a,b]? Assume that the…
- Question 52 – The number of permutations of the characters in LILAC so that no character appears in its original position, if the two L's are indistinguishable, is…
- Question 53 – Consider a non-pipelined processor operating at 2.5 GHz. It takes 5 clock cycles to complete an instruction. You are going to make a 5-stage pipeline…
- Question 54 – A processor has 64 registers and uses 16-bit instruction format. It has two types of instructions: I-type and R-type. Each I-type instruction contains…
- Question 55 – For n>2, let a\0,1\n be a non-zero vector. Suppose that x is chosen uniformly at random from \0,1\n. Then, the probability that i=1na ix i is an odd…
- Question 56 – Consider the following C functions. The return value of fun2(5) is .
- Question 57 – Consider the array representation of a binary min-heap containing 1023 elements. The minimum number of comparisons required to find the maximum in the…
- Question 58 – Consider the following C functions. The value returned by pp(3,4) is .
- Question 59 – Consider a graph G=(V,E), where V=\v 1,v 2,,v 100\, E=\(v i,v j) 1 i<j 100\, and weight of the edge (v i,v j) is i-j . The weight of minimum spanning…
- Question 60 – Consider the following set of processes, assumed to have arrived at time 0. Consider the CPU scheduling algorithms Shortest Job First (SJF) and Round…
- Question 61 – Consider the following language. L=\x\a,b\* number of a's in x is divisible by 2 but not divisible by 3\ The minimum number of states in a DFA that…
- Question 62 – Graph G is obtained by adding vertex s to K 3,4 and making s adjacent to every vertex of K 3,4. The minimum number of colours required to edge-colour…
- Question 63 – Consider a paging system that uses 1-level page table residing in main memory and a TLB for address translation. Each main memory access takes 100 ns…
- Question 64 – Consider a database implemented using B+ tree for file indexing and installed on a disk drive with block size of 4 KB. The size of search key is 12…
- Question 65 – Consider a TCP connection between a client and a server with the following specifications: the round trip time is 6 ms, the size of the receiver…