Exam Details
Computer Science & Information Technology (CS) SET 1 2017
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65
Duration
180 mins
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GATE & PSU CS - Previous Year Papers
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65questions
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Sample
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PYP
Computer Science & Information Technology (CS) SET 1 2017
Research in the workplace reveals that people work for many reason _____.
PYP
Computer Science & Information Technology (CS) SET 1 2017
After Rajendra chola returned from his voyage to Indonesia, he ____ to visit the temple in Thanjavur.
PYP
Computer Science & Information Technology (CS) SET 1 2017
Rahul Murali, Srinivas and Arul are seated around a square table. Rahul is sitting to the left of Murali. Srinivas is sitting to the right of Arul. Which of the following pairs are seated opposite each other?
PYP
Computer Science & Information Technology (CS) SET 1 2017
Find the number in the following such that it is a perfect cube of some number.
PYP
Computer Science & Information Technology (CS) SET 1 2017
The probability that a k-digit number does NOT contain the digits 0,5, or 9 is-
PYP
Computer Science & Information Technology (CS) SET 1 2017
A contour line joins locations having the same height above the mean sea level. The following is a contour plot of a geographical region. Contour lines are shown at 25m intervals in this plot. If in a flood, the water level rises to 525m, which of villages P, Q, R, S, T get submerged?
PYP
Computer Science & Information Technology (CS) SET 1 2017
“The hold of the nationalist imagination on our colonial past is such that anything inadequately or improperly nationalist is just not history” Which of the following statements best reflects the author’s opinion?
PYP
Computer Science & Information Technology (CS) SET 1 2017
The expression is equal to
PYP
Computer Science & Information Technology (CS) SET 1 2017
Six people are seated around a circular table. There are at least two men and two women. There are at least three right-handed persons. Every woman has a left-handed person to her immediate right. None of the women are right-handed. The number of women at the table is ?
PYP
Computer Science & Information Technology (CS) SET 1 2017
Arun, Gulab, Neel and Shweta must choose one shirt each from a pile of four shirts coloured red, pink, blue and white respectively. Arun dislikes the colour red and Shweta dislikes the colour white. Gulab and Neel like all the colours. In how many different ways can they choose the shirts so that no one has a shirt with a colour he or she dislikes?
PYP
Computer Science & Information Technology (CS) SET 1 2017
Let X be a Gaussian random variable mean 0 and variance σ2. Let Y = max(X, 0) where max (a, b) is the maximum of a and b. The median of Y is _____.
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the Karnaugh map given below, where x represents “don’t care” and blank represents 0. Assume for all inputs (a, b, c, d) the respective complements are also available. The above logic is implemented 2-input NOR gates only. The minimum number of NOR gates required is _____.
PYP
Computer Science & Information Technology (CS) SET 1 2017
The statement (¬p)⇒(¬q) is logically equivalent to which of the statements below ? I. p⇒qII. q⇒pIII. (¬q)∨pIV. (¬p)∨q
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the following table: Match the algorithms to the design paradigms they are based on.
PYP
Computer Science & Information Technology (CS) SET 1 2017
A sender S sends a message m to receiver R, which is digitally signed by S with its private key. In this scenario, one or more of the following security violations can take place. (I) S can launch a birthday attack to replace m with a fraudulent message. (II) A third party attacker can launch a birthday attack to replace m with a fraudulent message. (III) R can launch a birthday attack to replace m with a fraudulent message. Which of the following are possible security violations?
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the following grammar. What is FOLLOW (Q)?
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the language L given by the regular expression (a+b)*b(a+b) over the alphabet {a, b}. The smallest number of states needed in a deterministic finite-state automation (DFA) accepting L is ______.
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider a two-level cache hierarchy with L1 and L2 caches. An application incurs 1.4 memory accesses per instruction on average. For this application, the miss rate of L1 cache 0.1, the L2 cache experiences, on average, 7 misses per 1000 instructions. The miss rate of L2 expressed correct to two decimal places is _____.
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the following CPU processes with arrival times (in milliseconds) and length of CPU bursts (in milliseconds) as given below:
If the pre-emptive shortest remaining time first scheduling algorithm is used to schedule the processes, then the average waiting time across all processes is _______ milliseconds.
If the pre-emptive shortest remaining time first scheduling algorithm is used to schedule the processes, then the average waiting time across all processes is _______ milliseconds.
PYP
Computer Science & Information Technology (CS) SET 1 2017
Threads of a process share
PYP
Computer Science & Information Technology (CS) SET 1 2017
Let C1 …… Cn be scalars, not all zero, such that where are column vectors in Rn. Consider the set of linear equations Ax = b where A = [a1….an] and The set of equations has
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the C code fragment given below. typedef struct node{int data;node* next ;} node;void join(node* m, node* n){node* p = n;while (p->next != NULL){p = p->next;}p–>next = m;}Assuming that m and n point to valid NULL- terminated linked lists, invocation of join will
PYP
Computer Science & Information Technology (CS) SET 1 2017
The n-bit fixed-point representation of an unsigned real number real X uses f bits for the fraction part. Let The range of decimal values for X in this representation is
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the following intermediate program in three address code Which one of the following corresponds to a static single assignment form of the above code?
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the C struct defined below: struct data { int marks [100]; char grade; int cnumber; }; struct data student; The base address of student is available in register R1. The field student.grade can be accessed efficiently using
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider a TCP client and a TCP server running on two different machines. After completing data transfer, the TCP client calls close to terminate the connectional and a FIN segment is sent to the TCP server. Server-side TCP responds by sending an ACK which is received by the client-side TCP. As per the TCP connections state diagram (RFC 793), in which state does the client-side TCP connection wait for the FIN from the sever-side TCP?
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the following context-free grammar over the alphabet ∑ = {a,b,c} with S as the start symbol. Which one of the following represents the language generated by the above grammar?
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the first-order logic sentence
F: ∀ x (∃ y R(x,y)).
Assuming non-empty logical domains, which of the sentences below are implied by F?
I. ∃y (∃x R(x,y))
II. ∃y (∀x R(x,y))
III. ∀y (∃x R(x,y))
IV. ∼∃x (∀y ~R(x,y))
F: ∀ x (∃ y R(x,y)).
Assuming non-empty logical domains, which of the sentences below are implied by F?
I. ∃y (∃x R(x,y))
II. ∃y (∀x R(x,y))
III. ∀y (∃x R(x,y))
IV. ∼∃x (∀y ~R(x,y))
PYP
Computer Science & Information Technology (CS) SET 1 2017
When two 8-bit numbers A7…A0 and B7…B0 in 2’s complement representation (with A0 and B0 as the least significant bits) are added using a ripple-carry adder, the sum bits obtained are S7….S0 and the carry bits are C7…..C0. An overflow is said to have occurred if
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider a database that has the relation schema EMP (EmpId, EmpName, and DeptName). An instance of the schema EMP and a SQL query on it are given below. The output of executing the SQL query is _____.
PYP
Computer Science & Information Technology (CS) SET 1 2017
The following functional dependencies hold true for the relational schema R{V, W, X, Y, Z}: Which of the following is irreducible equivalent for this set of functional dependencies?
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the following functions from positive integers to real numbers: The CORRECT arrangement of the above functions in increasing order of asymptotic complexity is:
PYP
Computer Science & Information Technology (CS) SET 1 2017
Let T be a tree with 10 vertices. The sum of the degrees of all the vertices in T is _____.
PYP
Computer Science & Information Technology (CS) SET 1 2017
Let T be a binary search tree with 15 nodes. The minimum and maximum possible heights of T are: Note: The height of a tree with a single node is 0.
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the following C code: # include int * assignval (int *x, int val) { *x = val; return x; } void main ( ) { int * x= malloc (sizeof (int)); if (NULL = = x) return; x = assignval (x,0); if(x) { x=(int *) malloc (sizeof (int)); if (NULL = = x) return; x = assignval (x, 10); } printf(“%d\n”, *x); free (x); } The code suffers from which one of the following problems:
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider a combination of T and D flip flip-flop is connected to the input of the connected to the input of the D flip-flop is connected to the input of the T flip-flop and the output of the T Flip-flop is connected to the input of the D Flip-flop, Initially, both Q0 and Q1 are set to 1 (before the 1 clock cycle). The outputs
PYP
Computer Science & Information Technology (CS) SET 1 2017
The number of integers between 1 and 500 (both inclusive) that are divisible by 3 or 5 or 7 is ______.
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider a RISC machine where each instruction is exactly 4 bytes long. Conditional and unconditional branch instructions use PC- relative addressing mode with Offset specified in bytes to the target location of the branch instruction. Further the Offset is always with respect to the address of the next instruction in the program sequence. Consider the following instruction sequence. If the target of the branch instruction is i, then the decimal value of the Offset is _____.
PYP
Computer Science & Information Technology (CS) SET 1 2017
Considerfoofoo Initiallyval=3val=3 foo(val−−)foo(val−−)
is equivalent to
foo(val)foo(val)
val=val−1val=val−1
So,
foo(3)foo(3)
val=2val=2
foo(3)foo(3)callsfoo(3)foo(3)which in turn callsfoo(3)foo(3)this goes on So, here we can see thatfoo(3)foo(3)is called infinite number of times which causes memory overflow and abrupt termination
and one more thing to observe is infinite loop is not there since the val is decremented in the first iteration. Consider bar.
Here, we can see the val is not decrementing in the loop
So,
bar(3)bar(3)will callbar(2)bar(2)
bar(2)bar(2)will callbar(1)bar(1)
bar(1)bar(1)will callbar(0)→bar(0)→Here,bar(0)bar(0)return0return0 bar(1)bar(1)will callbar(0)bar(0)
bar(1)bar(1)will callbar(0)bar(0)
This will go on so here there is a problem of infinite loop but not abrupt termination since it does not cause memory overflow.
is equivalent to
foo(val)foo(val)
val=val−1val=val−1
So,
foo(3)foo(3)
val=2val=2
foo(3)foo(3)callsfoo(3)foo(3)which in turn callsfoo(3)foo(3)this goes on So, here we can see thatfoo(3)foo(3)is called infinite number of times which causes memory overflow and abrupt termination
and one more thing to observe is infinite loop is not there since the val is decremented in the first iteration. Consider bar.
Here, we can see the val is not decrementing in the loop
So,
bar(3)bar(3)will callbar(2)bar(2)
bar(2)bar(2)will callbar(1)bar(1)
bar(1)bar(1)will callbar(0)→bar(0)→Here,bar(0)bar(0)return0return0 bar(1)bar(1)will callbar(0)bar(0)
bar(1)bar(1)will callbar(0)bar(0)
This will go on so here there is a problem of infinite loop but not abrupt termination since it does not cause memory overflow.
PYP
Computer Science & Information Technology (CS) SET 1 2017
In a RSA cryptosystem a participant A uses two prime numbers p = 13 and q = 17 to generate her public and private keys. If the public key of A is 35. Then the private key of A is ______.
PYP
Computer Science & Information Technology (CS) SET 1 2017
Let A be an array of 31 numbers consisting of sequence of 0’s followed by a sequence of 1’s. The problem is to find the smallest index i that A[i] is 1 by probing the minimum numbers of locations in A. The worst case number of probes performed by an optimal algorithm is _____.
PYP
Computer Science & Information Technology (CS) SET 1 2017
If G is grammar with productions where S is the start variable, then which one of the following is not generated by G?
PYP
Computer Science & Information Technology (CS) SET 1 2017
The value of
PYP
Computer Science & Information Technology (CS) SET 1 2017
Instructions execution in a processor is divided into 5 stages. Instruction Fetch (IF), Instruction Decode (ID), Operand Fetch (OF), Execute (EX), and Write Back (WB), These stages take 5,4,20, 10 and 3 nanoseconds (ns) respectively. A pipelined implementation of the processor requires buffering between each pair of consecutive stages with a delay of 2ns. Two pipelined implementations of the processor are contemplated. (i) a naïve pipeline implementation (NP) with 5 stages and (ii) an efficient pipeline (EP) where the OF stage id divided into stages OF1 and OF2 with execution times of 12 ns and 8 ns respectively. The speedup (correct to two decimals places) achieved by EP over NP in executing 20 independent instructions with no hazards is _____.
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider a database that has the relation schemas EMP (EmpId, EmpName, DepId), and DEPT(DeptName, DeptId). Note that the DepId can be permitted to be NULL in the relation EMP. Consider the following queries on the database expressed in tuple relational calculus.
I. {t | ∃ u ∈ EMP (t[EMPName] = u[EmpName] ∧ ∀ v ∈ DEPT (t[DeptId] ≠ DeptId]))}
II. {t | ∃ u ∈ EMP (t[EMPName] = u[EmpName] ∧ ∃ v ∈ DEPT (t[DeptId] ≠ DeptId]))}
III. {t | ∃ u ∈ EMP (t[EMPName] = u[EmpName] ∧ ∃ v ∈ DEPT (t[DeptId] = DeptId]))}
I. {t | ∃ u ∈ EMP (t[EMPName] = u[EmpName] ∧ ∀ v ∈ DEPT (t[DeptId] ≠ DeptId]))}
II. {t | ∃ u ∈ EMP (t[EMPName] = u[EmpName] ∧ ∃ v ∈ DEPT (t[DeptId] ≠ DeptId]))}
III. {t | ∃ u ∈ EMP (t[EMPName] = u[EmpName] ∧ ∃ v ∈ DEPT (t[DeptId] = DeptId]))}
PYP
Computer Science & Information Technology (CS) SET 1 2017
Recall that Belady’s anomaly is that the pages-fault rate may increase as the number of allocated frames increases. Now consider the following statements: S1: Random page replacement algorithm (where a page chosen at random is replaced) suffers from Belady’s anomaly S2: LRU page replacement algorithm suffers from Belady’s anomaly Which of the following is CORRECT?
PYP
Computer Science & Information Technology (CS) SET 1 2017
The output of executing the following C program is ____. # include
int total(int v) { static int count = 0; while (v) { count += v & 1; v >>= 1; } return count; }
void main() { static int x = 0; int i = 5; for (; i> 0; i--) { x = x + total(i); } printf (“%d\n”, x) ; }
int total(int v) { static int count = 0; while (v) { count += v & 1; v >>= 1; } return count; }
void main() { static int x = 0; int i = 5; for (; i> 0; i--) { x = x + total(i); } printf (“%d\n”, x) ; }
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the following C program.
#include
#include
void printlength (char *s, char *t)
{ unsigned int c = 0; int len = ((strlen (s) - strlen (t)) > c) ? strlen (s) : strlen (t); printf("%d\n", len);
}
void main()
{ char *x = "abc"; char *y = "defgh"; printlength(x, y);
}
Recall that strlen is defined in string.h as returning a value of type size_t, which is an unsigned int .The output of the program is
#include
#include
void printlength (char *s, char *t)
{ unsigned int c = 0; int len = ((strlen (s) - strlen (t)) > c) ? strlen (s) : strlen (t); printf("%d\n", len);
}
void main()
{ char *x = "abc"; char *y = "defgh"; printlength(x, y);
}
Recall that strlen is defined in string.h as returning a value of type size_t, which is an unsigned int .The output of the program is
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the following languages over the alphabet ∑= {a,b,c}. Let L1 = {an bncm | m, n >= 0 } and L2 = {ambncn| m, n >= 0}.
Which of the following are context-free languages ?
I. L1 ∪ L2 II. L1 ∩ L2
Which of the following are context-free languages ?
I. L1 ∪ L2 II. L1 ∩ L2
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider a 2-way set associative cache with 256 blocks and uses LRU replacement, Initially the cache is empty. Conflict misses are those misses which occur due the contention of multiple blocks for the same cache set. Compulsory misses occur due to first time access to the block. The following sequence of accesses to memory blocks. (0,128,256,128,0,128,256,128,1,129,257,129,1,129,257,129) is repeated 10 times. The number of conflict misses experienced by the cache is __________.
PYP
Computer Science & Information Technology (CS) SET 1 2017
Let u and v be two vectors in R2 whose Euclidean norms satisfy ∥u∥=2∥v∥. What is the value of α such that w=u+αv bisects the angle between u and v?
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the following grammar: stmt → if exp r then else exp r ;stmt 0 exp r → termrelop term term term → id | number if → a | b | c number → [0…9] where relop is a relational operate (e.g <, >,….) ---O refers to the empty statement, and if, then, else are terminals. Consider a program P following the above grammar containing ten if terminals. The number of control flows paths in P is _____. For example the program if e1 then e2 else e3 has 2 controls flow paths e1→ e2 and e1 → e3
PYP
Computer Science & Information Technology (CS) SET 1 2017
In a database system, unique time stamps are assigned to each transaction using Lamport’s logical clock. Let TS(T1) and TS(T2) be the timestamps of transactions T1 and T2 respectively. Besides, T1 holds a lock on the resource R, and T2 has requested a conflicting lock on the same resource R. The following algorithm is used to prevent deadlocks in the database system assuming that a killed transaction is restarted with the same timestamp. if TS(T2) < TS(T1) then T1 is killed else T2 waits. Assume any transactions that is not killed terminates eventually. Which of the following is TRUE about the database system that uses the above algorithm to prevent deadlocks?
PYP
Computer Science & Information Technology (CS) SET 1 2017
Let A and B be infinite alphabets and let # be a symbol outside both A and B. Let f be a total functional from A* to B*. We say f is computable if there exists a Turning machine M which given an input x in A*, always halts with f(x) on its tape. Let Lf denote the language Which of the following statements is true:
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the expression Let X be the minimum number of registers required by an optimal code generation (without any register spill) algorithm for a load/store architecture in which (i) only loads and store instructions can have memory operands and (ii) arithmetic instructions can have only register or immediate operands. The value of X is _____.
PYP
Computer Science & Information Technology (CS) SET 1 2017
Let G = (V, E) be any connected undirected edge-weighted graph. The weights of the edges in E are positive and distinct. Consider the following statements: (I) Minimum spanning tree of G is always unique. (II) Shortest path between any two vertices of G is always unique. Which of the above statements is/are necessarily true?
PYP
Computer Science & Information Technology (CS) SET 1 2017
A multithreaded program P executes with x number of threads and uses y number of locks for ensuring mutual exclusion while operating on shared memory locations. All locks in the program are non-re-entrant, i.e., if a thread holds a lock l, then it cannot re-acquire lock l without releasing it. If a thread is unable to acquire a lock, it blocks until the lock becomes available. The minimum value of x and the minimum value of y together for which execution of P can result in a deadlock are:
PYP
Computer Science & Information Technology (CS) SET 1 2017
The values of parameters for the Stop-and – Wait ARQ protocol are as given below: Bit rate of the transmission channel = 1 Mbps Propagation delay from sender to receiver = 0.75 ms Time to process a frame = 0.25 ms Number of bytes in the information frame = 1980 Number of bytes in the acknowledge frame = 20 Number of overhead bytes in the information frame = 20 Assume that there are no transmission errors. Then the transmission efficiency (expressed in percentage) of the Stop-and – Wait ARQ protocol for the above parameters is _____.
PYP
Computer Science & Information Technology (CS) SET 1 2017
A computer network uses polynomials over GF(2) for error checking with 8 bits as information bits and uses x3 + x + 1 as the generator polynomial to generate the check bits. In this network, the message 01011011 is transmitted as
PYP
Computer Science & Information Technology (CS) SET 1 2017
Let p, q, and r be propositions and the expression (p → q) → r be a contradiction. Then, the expression (r → p) → q is
PYP
Computer Science & Information Technology (CS) SET 1 2017
A cache memory unit with capacity of N words and block size of B words is to be designed. If it is designed as a direct mapped cache, the length of the TAG field is 10 bits. If the cache unit is now designed as a 16-way set-associative cache, the length of the TAG field is ______ bits.
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the following two functions. void fun1 (int n) { if (n == 0 ) return; printf (“%d” , n); fun2 (n - 2); printf (“%d” , n); } void fun2 (int n) { if (n = = 0) return ; printf (“%d” , n); fun1(++n) ; printf (“%d” , n); } The output printed when fun1(5) is called is
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider a database that has the relation schema CR (StudentName, CourseName). An instance of the schema CR is as given below. The following query is made on the database. The number of rows in T2 is _____.
PYP
Computer Science & Information Technology (CS) SET 1 2017
Let A be real valued square symmetric matrix of rank 2 with Consider the following statements. (I) One eigen value must be in [-5, 5] (II) The eigen value with the largest magnitude must be strictly greater than 5. Which of the above statements about eigen values of A is/are necessarily CORRECT?
PYP
Computer Science & Information Technology (CS) SET 1 2017
Consider the context-free grammars over the alphabet {a,b,c} given below. S and T are non-terminals The language is
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