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GATE CS question library

Practise GATE CS Computer Science previous year questions free. Browse by subject, syllabus topic, year and question type, with answers and available solutions.

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20 on this page
Official PYQ2021Theory of ComputationRegular and Context-free LanguagesMCQ · 1 mark
Let ⟨M⟩\langle M \rangle denote an encoding of an automaton MM. Suppose that Σ={0,1}\Sigma = \{0,1\}. Which of the following languages is/are NOT\text{NOT} recursive?
Official PYQ2021DatabasesTransactions and Concurrency ControlMCQ · 1 mark
Suppose a database system crashes again while recovering from a previous crash. Assume checkpointing is not done by the database either during the transactions or during recovery. Which of the following statements is/are correct?
Official PYQ2021Operating SystemSystem CallsMSQ · 1 mark
Which of the following standard CC library functions will always invoke a system call when executed from a single-threaded process in a UNIX/Linux\text{UNIX/Linux} operating system?
Official PYQ2021Operating SystemFile SystemsMSQ · 1 mark
Consider a linear list based directory implementation in a file system. Each directory is a list of nodes, where each node contains the file name along with the file metadata, such as the list of pointers to the data blocks. Consider a given directory foo\textsf{foo}. Which of the following operations will necessarily require a full scan of foo\textsf{foo} …
Official PYQ2021Engineering MathematicsGraphs: Connectivity, Matching, ColouringNAT · 1 mark
In an undirected connected planar graph GG, there are eight vertices and five faces. The number of edges in GG is _________.
Official PYQ2021AlgorithmsMinimum Spanning TreesNAT · 1 mark
Consider the following undirected graph with edge weights as shown: The number of minimum-weight spanning trees of the graph is ___________.
Official PYQ2021Engineering MathematicsCombinatorics: Counting, Recurrence Relations, Generating FunctionsNAT · 1 mark
There are 66 jobs with distinct difficulty levels, and 33 computers with distinct processing speeds. Each job is assigned to a computer such that: The fastest computer gets the toughest job and the slowest computer gets the easiest job. Every computer gets at least one job. The number of ways in which this can be done is ___________.
Official PYQ2021Engineering MathematicsProbability: Random Variables and DistributionsNAT · 1 mark
The lifetime of a component of a certain type is a random variable whose probability density function is exponentially distributed with parameter 22. For a randomly picked component of this type, the probability that its lifetime exceeds the expected lifetime (rounded to 22 decimal places) is ____________.
Official PYQ2021Engineering MathematicsCalculus: Limits, Continuity, DifferentiabilityNAT · 1 mark
Consider the following expression.lim⁡x→−32x+22−4x+3\displaystyle \lim_{x\rightarrow-3}\frac{\sqrt{2x+22}-4}{x+3}The value of the above expression (rounded to 2 decimal places) is ___________.
Official PYQ2021Programming and Data StructuresArrays, Stacks and QueuesNAT · 1 mark
Consider the following sequence of operations on an empty stack.push(54);push(52);pop();push(55);push(62);s=pop();\textsf{push}(54);\textsf{push}(52);\textsf{pop}();\textsf{push}(55);\textsf{push}(62);\textsf{s}=\textsf{pop}();Consider the following sequence of operations on an empty queue. …
Official PYQ2021Computer Organization and ArchitectureMemory Hierarchy: Cache, Main Memory and Secondary StorageNAT · 1 mark
Consider a computer system with a byte-addressable primary memory of size 2322^{32} bytes. Assume the computer system has a direct-mapped cache of size 32 KB\text{32 KB} (1 KB\text{1 KB} = 2102^{10} bytes), and each cache block is of size 6464 bytes. The size of the tag field is __________ bits.
Official PYQ2021DatabasesTuple Calculus and SQLNAT · 1 mark
A relation r(A,B)r(A, B) in a relational database has 12001200 tuples. The attribute AA has integer values ranging from 66 to 2020, and the attribute BB has integer values ranging from 11 to 2020. Assume that the attributes AA and BB are independently distributed. The estimated number of tuples in the output of …
Official PYQ2021Digital LogicNumber Representations (Fixed and Floating Point)NAT · 1 mark
Consider the following representation of a number in IEEE 754\text{IEEE 754} single-precision floating point format with a bias of 127127.S:1E:  10000001F:  11110000000000000000000S: 1\quad\quad E:\; 10000001\quad\quad F:\;11110000000000000000000 Here S,  ES, \;E and FF denote the sign, exponent, and fraction components of the floating point representation. The decimal value corresponding to the …
Official PYQ2021Operating SystemCPU SchedulingNAT · 1 mark
Three processes arrive at time zero with CPU\text{CPU} bursts of 16,  2016,\;20 and 1010 milliseconds. If the scheduler has prior knowledge about the length of the CPU\text{CPU} bursts, the minimum achievable average waiting time for these three processes in a non-preemptive scheduler (rounded to nearest integer) is _____________ milliseconds.
Official PYQ2021Compiler DesignSyntax-directed TranslationMCQ · 2 marks
​​​Consider the following grammar (that admits a series of declarations, followed by expressions) and the associated syntax directed translation (SDT)\text{(SDT)} actions, given as pseudo-code …
Official PYQ2021DatabasesRelational Model: Relational AlgebraMCQ · 2 marks
The following relation records the age of 500500 employees of a company, where empNoempNo (indicating the employee number) is the key: empAge(empNo‾,age)empAge(\underline{empNo},age) Consider the following relational algebra expression: ΠempNo(empAge⋈(age>age1)ρempNo1,age1(empAge))\Pi_{empNo}(empAge \Join_{(age>age1)} \rho_{empNo1,age1}(empAge)) What does the above expression generate?
Official PYQ2021Digital LogicSequential CircuitsMCQ · 2 marks
Consider a 33-bit counter, designed using TT flip-flops, as shown below: Assuming the initial state of the counter given by PQR\text{PQR} as 000000, what are the next three states?
Official PYQ2021Computer NetworksData Link Layer: Framing, Error Detection, MAC, Ethernet BridgingMCQ · 2 marks
Assume that a 1212-bit Hamming codeword consisting of 88-bit data and 44 check bits is d8d7d6d5c8d4d4d3d2c4d1c2c1d_8d_7d_6d_5c_8d_4d_ 4d_3d_2c_4d_1c_2c_1, where the data bits and the check bits are given in the following tables: …
Official PYQ2021Compiler DesignParsing (LL, LR)MCQ · 2 marks
Consider the following context-free grammar where the set of terminals is {a,b,c,d,f}\{a,b,c,d,f\}. …
Official PYQ2021AlgorithmsAsymptotic Worst Case Time and Space ComplexityMCQ · 2 marks
Consider the following recurrence relation. T(n)={T(n∕2)+T(2n∕5)+7nif  n>01if  n=0T\left ( n \right )=\left\{\begin{array} {lcl} T(n ∕ 2)+T(2n∕5)+7n & \text{if} \; n>0\\1 & \text{if}\; n=0 \end{array}\right. Which one of the following options is correct?