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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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Official PYQ2009Operating SystemI/O SchedulingMCQ · 1 mark
A hard disk has 6363 sectors per track, 1010 platters each with 22 recording surfaces and 10001000 cylinders. The address of a sector is given as a triple ⟨c,h,s⟩\langle c, h, s \rangle, where cc is the cylinder number, hh is the surface number and ss is the sector number. Thus, the 0th^{th} sector is addresses as ⟨0,0,0⟩\langle 0, 0, 0 \rangle, …
Official PYQ2009AlgorithmsAlgorithm Design: Dynamic ProgrammingMCQ · 1 mark
A sub-sequence of a given sequence is just the given sequence with some elements (possibly none or all) left out. We are given two sequences X[m]X[m] and Y[n]Y[n] of lengths mm and nn, respectively with indexes of XX and YY starting from 00. We wish to find the length of the longest common sub-sequence (LCS) of X[m]X[m] and Y[n]Y[n] as …
Official PYQ2009DatabasesNormal FormsMCQ · 1 mark
Consider the following relational schema: Suppliers(sid:integer‾, sname:string, city:string, street:string)\text{Suppliers}(\underline{\text{sid:integer}},\text{ sname:string, city:string, street:string}) Parts(pid:integer‾, pname:string, color:string)\text{Parts}(\underline{\text{pid:integer}}, \text{ pname:string, color:string}) Catalog(sid:integer, pid:integer‾,cost:real)\text{Catalog}(\underline {\text{sid:integer, pid:integer}}, \text{cost:real}) Assume that, in the suppliers relation above, …
Official PYQ2009Computer NetworksTransport Layer: Flow Control, Congestion Control, UDP, TCP, SocketsMCQ · 1 mark
Frames of 1000 bits1000\text{ bits} are sent over a 10610^6 bps duplex link between two hosts. The propagation time is 25ms25ms. Frames are to be transmitted into this link to maximally pack them in transit (within the link). Let II be the minimum number of bits (I)(I) that will be required to represent the sequence numbers distinctly assuming that no time …
Official PYQ2009Programming and Data StructuresBinary HeapsMCQ · 1 mark
Consider a binary max-heap implemented using an array. Which one of the following array represents a binary max-heap?
Official PYQ2009Programming and Data StructuresBinary HeapsMCQ · 1 mark
Consider a binary max-heap implemented using an array. What is the content of the array after two delete operations on {25,14,16,13,10,8,12}\left\{25,14,16,13,10,8,12\right\}
Official PYQ2009Computer NetworksTransport Layer: Flow Control, Congestion Control, UDP, TCP, SocketsMCQ · 1 mark
Frames of 1000 bits\text{1000 bits} are sent over a 10610^6 bps\text{bps} duplex link between two hosts. The propagation time is 25 ms\text{25 ms}. Frames are to be transmitted into this link to maximally pack them in transit (within the link). What is the minimum number of bits (I)(I) that will be required to represent the sequence numbers distinctly? Assume …
Official PYQ2009AlgorithmsAlgorithm Design: Dynamic ProgrammingMCQ · 1 mark
A sub-sequence of a given sequence is just the given sequence with some elements (possibly none or all) left out. We are given two sequences X[m]X[m] and Y[n]Y[n] of lengths mm and nn, respectively with indexes of XX and YY starting from 00. We wish to find the length of the longest common sub-sequence (LCS) of X[m]X[m] and Y[n]Y[n] as …
Official PYQ2009DatabasesTuple Calculus and SQLMCQ · 1 mark
Consider the following relational schema: Suppliers(sid:integer‾, sname:string, city:string, street:string)\text{Suppliers}(\underline{\text{sid:integer}},\text{ sname:string, city:string, street:string}) Parts(pid:integer‾, pname:string, color:string)\text{Parts}(\underline{\text{pid:integer}}, \text{ pname:string, color:string}) Catalog(sid:integer, pid:integer‾,cost:real)\text{Catalog}(\underline {\text{sid:integer, pid:integer}}, \text{cost:real}) Consider the following relational query on the …
Official PYQ2009Software Engineering (Historical)MCQ · 1 mark
Which of the following statements are TRUE? The context diagram should depict the system as a single bubble. External entities should be identified clearly at all levels of DFDs. Control information should not be represented in a DFD. A data store can be connected wither to another data store or to an external entity.
Official PYQ2009Software Engineering (Historical)MCQ · 1 mark
Consider the following statements about the cyclomatic complexity of the control flow graph of a program module. Which of these are TRUE? The cyclomatic complexity of a module is equal to the maximum number of linearly independent circuits in the graph. The cyclomatic complexity of a module is the number of decisions in the module plus one, where a decision …
Official PYQ2009Operating SystemI/O SchedulingMCQ · 1 mark
A hard disk has 6363 sectors per track, 1010 platters each with 22 recording surfaces and 10001000 cylinders. The address of a sector is given as a triple ⟨c,h,s⟩\langle c, h, s \rangle, where cc is the cylinder number, hh is the surface number and ss is the sector number. Thus, the 0th^{th} sector is addresses as ⟨0,0,0⟩\langle 0, 0, 0 \rangle, …
Official PYQ2009Computer NetworksData Link Layer: Framing, Error Detection, MAC, Ethernet BridgingMCQ · 1 mark
Let G(x)G(x) be the generator polynomial used for CRC checking. What is the condition that should be satisfied by G(x)G(x) to detect odd number of bits in error?
Official PYQ2009Computer NetworksConcept of Layering: OSI and TCP/IP Protocol StacksMCQ · 1 mark
In the RSA public key cryptosystem, the private and public keys are (e,n)(e, n) and (d,n)(d, n) respectively, where n=p×qn=p \times q and pp and qq are large primes. Besides, nn is public and pp and qq are private. Let MM be an integer such that 0<M<n0<M<n and ϕ(n)=(p−1)(q−1)\phi(n) = (p-1)(q-1). Now consider the following equations. …
Official PYQ2009Computer NetworksTransport Layer: Flow Control, Congestion Control, UDP, TCP, SocketsMCQ · 1 mark
While opening a TCPTCP connection, the initial sequence number is to be derived using a time-of-day (ToD) clock that keeps running even when the host is down. The low order 3232 bits of the counter of the ToD clock is to be used for the initial sequence numbers. The clock counter increments once per milliseconds. The maximum packet lifetime is given to be …
Official PYQ2009DatabasesTransactions and Concurrency ControlMCQ · 1 mark
Consider two transactions T1T_1 and T2T_2, and four schedules S1,S2,S3,S4S_1, S_2, S_3, S_4, of T1T_1 and T2T_2 as given below: T1:R1[x]W1[x]W1[y]T_1: R_1[x]W_1[x]W_1[y] T2:R2[x]R2[y]W2[y]T_2: R_2[x]R_2[y]W_2[y] S1:R1[x]R2[x]R2[y]W1[x]W1[y]W2[y]S_1: R_1[x]R_2[x]R_2[y] W_1[x] W_1[y] W_2[y] S2:R1[x]R2[x]R2[y]W1[x]W2[y]W1[y]S_2: R_1[x]R_2[x]R_2[y] W_1[x] W_2[y] W_1[y] S3:R1[x]W1[x]R2[x]W1[y]R2[y]W2[y]S_3: R_1[x]W_1[x]R_2[x] W_1[y] R_2[y] W_2[y] …
Official PYQ2009DatabasesFile Organization and Indexing (B and B+ Trees)MCQ · 1 mark
The following key values are inserted into a B+B^+ - tree in which order of the internal nodes is 33, and that of the leaf nodes is 22, in the sequence given below. The order of internal nodes is the maximum number of tree pointers in each node, and the order of leaf nodes is the maximum number of data items that can be stored in it. The B+B^+ - …
Official PYQ2009DatabasesTuple Calculus and SQLMCQ · 1 mark
Let RR and SS be relational schemes such that R={a,b,c}R=\{a,b,c\} and S={c}.S=\{c\}. Now consider the following queries on the database: πR−S(r)−πR−S(πR−S(r)×s−πR−S,S(r))\pi_{R-S}(r) - \pi_{R-S} \left (\pi_{R-S} (r) \times s - \pi_{R-S,S}(r)\right ) …
Official PYQ2009Compiler DesignParsing (LL, LR)MCQ · 1 mark
Which of the following statements are TRUE? There exist parsing algorithms for some programming languages whose complexities are less than Θ(n3)\Theta(n^3) A programming language which allows recursion can be implemented with static storage allocation. No L-attributed definition can be evaluated in the framework of bottom-up parsing. Code improving …
Official PYQ2009Theory of ComputationRegular Expressions and Finite AutomataMCQ · 1 mark
The above DFA accepts the set of all strings over {0,1}\{0,1\} that