Consider a relation geq which represents “greater than or equal to”, that is, (x,y) ∈ geq only if y >= x.create table geq( ib integer not null ub integer not null primary key 1b foreign key (ub) references geq on delete cascade )Which of the following is possible if a tuple (x,y) is deleted?

The deletion of (x,y) is prohibited

A tuple (z,w) with z > y is deleted

A tuple (z,w) with z > x is deleted

A tuple (z,w) with w < x is deleted

The deletion of (x,y) is prohibited

Suppose the adjacency relation of vertices in a graph is represented in a table Adj(X,Y). Which of the following queries cannot be expressed by a relational algebra expression of constant length?

List of all vertices adjacent to a given vertex

List all vertices which have self loops

List all vertices which belong to cycles of less than three vertices

List all vertices reachable from a given vertex

The relation book (title, price) contains the titles and prices of different books. Assuming that no two books have the same price, what does the following SQL query list? select title from book as B where (select count(*) from book as T where T.price > B.price) < 5

Titles of the four most expensive books

Title of the fifth most inexpensive book

Title of the fifth most expensive bookTitles of the five most expensive books

Titles of the five most expensive books

In strict two-phase locking protocol

All exclusive mode locks taken by transaction can be released before transaction commits

All exclusive mode lock taken by transaction be held until transaction commits

All exclusive mode locks taken by transaction can be released before transaction commits

All locks can be released before transaction commits

Consider a schema R(A,B,C,D) and functional dependencies A->B and C->D. Then the decomposition of R into R1(AB) and R2(CD) is

not dependency preserving and not lossless join

dependency preserving and lossless join

lossless join but not dependency preserving

dependency preserving but not lossless join

not dependency preserving and not lossless join

Suppose a database schedule S involves transactions T1, ....Tn. Construct the precedence graph of S with vertices representing the transactions and edges representing the conflicts. If S is serializable, which one of the following orderings of the vertices of the precedence graph is guaranteed to yield a serial schedule?

Ascending order of transaction indices

Consider the following three table to store student enrollements in different courses.Student(EnrollNo, Name)Course(CourseID, Name)EnrollMents(EnrollNo, CourseID) (EnrollNo,CourseID are primary keys)What does the following query do?SELECT S.NameFROM Student S, Course C, Enrollments EWHERE S.EnrollNo = E.EnrollNo AND C.Name = "DBMS" AND E.CourseID = C.CourseID AND S.EnrollNo IN (SELECT S2.EnrollNo FROM Student S2, Course C2, Enrollments E2 WHERE S2.EnrollNo = E2.EnrollNo AND E2.CourseID = C2.CourseID C2.Name = "OS")

Name of all students who are either enrolled in "DBMS" or "OS" or both

Name of all students who are either enrolled in "DBMS" or "OS" courses

Name of all students who are enrolled in "DBMS" and "OS"

Name of all students who are either enrolled in "DBMS" or "OS" or both

In SQL, relations can contain null values, and comparisons with null values are treated as unknown. Suppose all comparisons with a null value are treated as false. Which of the following pairs is not equivalent?

x = 5 AND x> 4 and x < 6, where x is an integer

What is the control unit’s function in the CPU?

To transfer data to primary storage

For interval arithmetic best rounding technique use is ………..

Rounding to plus and minus infinity

406 + Mcqs in GATE cse question paper Page 5 McqOptions

201.	Consider a relation geq which represents “greater than or equal to”, that is, (x,y) ∈ geq only if y >= x.create table geq( ib integer not null ub integer not null primary key 1b foreign key (ub) references geq on delete cascade )Which of the following is possible if a tuple (x,y) is deleted?
A.	A tuple (z,w) with z > y is deleted
B.	A tuple (z,w) with z > x is deleted
C.	A tuple (z,w) with w < x is deleted
D.	The deletion of (x,y) is prohibited
Answer» D. The deletion of (x,y) is prohibited

Discussion

202.	Suppose the adjacency relation of vertices in a graph is represented in a table Adj(X,Y). Which of the following queries cannot be expressed by a relational algebra expression of constant length?
A.	List of all vertices adjacent to a given vertex
B.	List all vertices which have self loops
C.	List all vertices which belong to cycles of less than three vertices
D.	List all vertices reachable from a given vertex
Answer» E.

Discussion

203.	The relation book (title, price) contains the titles and prices of different books. Assuming that no two books have the same price, what does the following SQL query list? select title from book as B where (select count(*) from book as T where T.price > B.price) < 5
A.	Titles of the four most expensive books
B.	Title of the fifth most inexpensive book
C.	Title of the fifth most expensive bookTitles of the five most expensive books
D.	Titles of the five most expensive books
Answer» E.

Discussion

204.	A table 'student' with schema (roll, name, hostel, marks), and another table 'hobby' with schema (roll, hobbyname) contains records as shown below:Table: StudentROLL NAME HOSTEL MARKS1798 Manoj Rathod 7 952154 Soumic Banerjee 5 682369 Gumma Reddy 7 862581 Pradeep Pendse 6 922643 Suhas Kulkarni 5 782711 Nitin Kadam 8 722872 Kiran Vora 5 922926 Manoj Kunkalikar 5 942959 Hemant Karkhanis 7 883125 Rajesh Doshi 5 82 Table: hobbyROLL HOBBYNAME1798 chess1798 music2154 music2369 swimming2581 cricket2643 chess2643 hockey2711 volleyball2872 football2926 cricket2959 photography3125 music3125 chess The following SQL query is executed on the above tables:select hostelfrom student natural join hobbywhere marks > = 75 and roll between 2000 and 3000;Relations S and H with the same schema as those of these two tables respectively contain the same information as tuples. A new relation S’ is obtained by the following relational algebra operation: S’ = ∏hostel ((σs.roll = H.roll (σmarks > 75 and roll > 2000 and roll < 3000 (S)) X (H)) The difference between the number of rows output by the SQL statement and the number of tuples in S’ is
A.	6
B.	4
C.	2
D.	0
Answer» C. 2

Discussion

205.	Two transactions T₁ and T₂ are given as follows:
A.	12
B.	13
C.	14
D.	15
Answer» E.

Discussion

206.	In an inventory management system implemented at a trading corporation, there are several tables designed to hold all the information. Amongst these, the following two tables hold information on which items are supplied by which suppliers, and which warehouse keeps which items along with the stock-level of these items. Supply = (supplierid, itemcode) Inventory = (itemcode, warehouse, stocklevel) For a specific information required by the management, following SQL query has been writtenSelect distinct STMP.supplieridFrom Supply as STMPWhere not unique (Select ITMP.supplierid From Inventory, Supply as ITMP Where STMP.supplierid = ITMP.supplierid And ITMP.itemcode = Inventory.itemcode And Inventory.warehouse = 'Nagpur');For the warehouse at Nagpur, this query will find all suppliers who
A.	do not supply any item
B.	supply exactly one item
C.	supply one or more items
D.	supply two or more items
Answer» E.

Discussion

207.	In strict two-phase locking protocol
A.	All exclusive mode lock taken by transaction be held until transaction commits
B.	All exclusive mode locks taken by transaction can be released before transaction commits
C.	All locks can be released before transaction commits
D.	None of these
Answer» B. All exclusive mode locks taken by transaction can be released before transaction commits

Discussion

208.	Consider a schema R(A,B,C,D) and functional dependencies A->B and C->D. Then the decomposition of R into R1(AB) and R2(CD) is
A.	dependency preserving and lossless join
B.	lossless join but not dependency preserving
C.	dependency preserving but not lossless join
D.	not dependency preserving and not lossless join
Answer» D. not dependency preserving and not lossless join

Discussion

209.	Suppose a database schedule S involves transactions T1, ....Tn. Construct the precedence graph of S with vertices representing the transactions and edges representing the conflicts. If S is serializable, which one of the following orderings of the vertices of the precedence graph is guaranteed to yield a serial schedule?
A.	Topological order
B.	Depth-first order
C.	Breadth-first order
D.	Ascending order of transaction indices
Answer» B. Depth-first order

Discussion

210.	Consider the following three table to store student enrollements in different courses.Student(EnrollNo, Name)Course(CourseID, Name)EnrollMents(EnrollNo, CourseID) (EnrollNo,CourseID are primary keys)What does the following query do?SELECT S.NameFROM Student S, Course C, Enrollments EWHERE S.EnrollNo = E.EnrollNo AND C.Name = "DBMS" AND E.CourseID = C.CourseID AND S.EnrollNo IN (SELECT S2.EnrollNo FROM Student S2, Course C2, Enrollments E2 WHERE S2.EnrollNo = E2.EnrollNo AND E2.CourseID = C2.CourseID C2.Name = "OS")
A.	Name of all students who are either enrolled in "DBMS" or "OS" courses
B.	Name of all students who are enrolled in "DBMS" and "OS"
C.	Name of all students who are either enrolled in "DBMS" or "OS" or both
D.	None of the above
Answer» C. Name of all students who are either enrolled in "DBMS" or "OS" or both

Discussion

211.	Consider the relations r1(P, Q, R) and r2(R, S, T) with primary keys P and R respectively. The relation r1 contains 2000 tuples and r2 contains 2500 tuples. The maximum size of the join r1⋈ r2 is :
A.	2000
B.	2500
C.	4500
D.	5000
Answer» B. 2500

Discussion

212.	In SQL, relations can contain null values, and comparisons with null values are treated as unknown. Suppose all comparisons with a null value are treated as false. Which of the following pairs is not equivalent?
A.	x = 5 AND not(not(x = 5))
B.	x = 5 AND x> 4 and x < 6, where x is an integer
C.	x < 5 AND not (x = 5)
D.	None of the above
Answer» D. None of the above

Discussion

213.	To prevent signals from colliding on the bus, ……………….. Prioritize access to memory by I/o channels and processors.
A.	A register
B.	Interrupts
C.	The processor scheduler
D.	A controller
Answer» E.

Discussion

214.	Halt operation comes under ………
A.	Data transfer
B.	Control transfer
C.	Conversion
D.	I/O transfer
Answer» C. Conversion

Discussion

215.	What is the maximum number of different Boolean functions involving n boolean variables?
A.	n²
B.	2ⁿ
C.	2²ⁿ
D.	2n²
Answer» D. 2n²

Discussion

216.	Consider the following subtraction and Identify the correct answer.
A.	(135103.412)₈
B.	(564411.412)₈
C.	(564411.205)₈
D.	(135103.205)₈
Answer» B. (564411.412)₈

Discussion

217.	The register which keeps track of the execution of a program and which contains the memory address of the instruction currently being executed is known as …………
A.	Index – Register
B.	Memory address register
C.	Program Counter
D.	Instruction registers
Answer» D. Instruction registers

Discussion

218.	What is the control unit’s function in the CPU?
A.	To decode program instructions
B.	To transfer data to primary storage
C.	To perform logical operations
D.	To store program instructions
Answer» B. To transfer data to primary storage

Discussion

219.	Find the radix 5 representation for the following decimal representation:
A.	(134)₅
B.	(124)₅
C.	(114)₅
D.	(144)₅
Answer» C. (114)₅

Discussion

220.	A 5 stage pipeline with the stages taking 1, 1, 3, 1, 1 units of time has a through put of
A.	1⁄3
B.	1⁄7
C.	7
D.	3
Answer» B. 1⁄7

Discussion

221.	A 2 level memory has an average access time of 30 ns with cache and memory access time as 20 ns and 150 ns respectively. What is the hit ratio?
A.	80%
B.	93%
C.	70%
D.	99%
Answer» C. 70%

Discussion

222.	Consider a hypothetical k-map in which essential prime implicants covering all the min – terms except two. Each of the left over min – term is covered by 3 different redundant prime implicants. What would be the no of minimal expressions denoted by the map?
A.	3
B.	8
C.	9
D.	16
Answer» D. 16

Discussion

223.	How many Boolean functions are possible with 2 trinary variables?
A.	256
B.	512
C.	1024
D.	128
Answer» C. 1024

Discussion

224.	Which one is required while establishing the communication link between CPU and peripherals?
A.	Index register
B.	Instruction register
C.	Memory address register
D.	Memory data register
Answer» E.

Discussion

225.	Which of the following holds data and processing instructions temporarily until the CPU needs it??
A.	ROM
B.	Control unit
C.	Main memory
D.	Coprocessor chips
Answer» D. Coprocessor chips

Discussion

226.	A computer system has 4k – word cache organized in a block – set-associative manner, with 4 blocks per set, 64 words per block, memory is word addressable. The number of bits in the SET and WORD fields of the main memory address format is
A.	15, 4
B.	6, 4
C.	7, 6
D.	4, 6
Answer» E.

Discussion

227.	Which of the following is not involved in a memory write operation?
A.	MAR
B.	PC
C.	MDR
D.	Data bus
Answer» C. MDR

Discussion

228.	A 4-bit carry look ahead adder, which adds two 4-bit numbers, is designed using AND, OR, NOT, NAND, NOR gates only. Assuming that all the inputs are available in both complemented and uncomplemented forms and the delay of each gate is one time unit, what is the overall propagation delay of the adder? Assume that the carry network has been implemented using two-level AND-OR logic.
A.	4 time units
B.	6 time units
C.	10 time units
D.	12 time units
Answer» C. 10 time units

Discussion

229.	System calls are usually invoked by using
A.	2 and 3
B.	1 and 3
C.	1, 2, 3 & 4
D.	3 & 4
Answer» B. 1 and 3

Discussion

230.	Define the connective * for the Boolean variable X and Y as :
A.	Only P and Q are valid.
B.	Only Q and R are valid.
C.	Only P and R are valid.
D.	All P, Q, R are valid.
Answer» E.

Discussion

231.	(1217)₈ is equivalent to
A.	(1217)₁₆
B.	(028F)₁₆
C.	(2297)₁₀
D.	(0B17)₁₆
Answer» C. (2297)₁₀

Discussion

232.	…………… improve system performance by temporarily storing data during transfers s/w devices or processers that operate at different speeds.
A.	Caches
B.	Controllers
C.	Buffers
D.	Registers
Answer» D. Registers

Discussion

233.	The bus system of a machine has the following propagation delay times 40 ns for the signals to propagate through the multiplexers, 90ns to perform the ADD operating in the ALU, 30ns delay in the destination decoder, and 20ns to store the data into the destination register. What is the minimum cycle time that can be used for the clock?
A.	120ns
B.	150ns
C.	960ns
D.	180ns
Answer» C. 960ns

Discussion

234.	Which of the following register processors used for fetch and execute operations?
A.	1 and 3
B.	1 and 2
C.	2 and 3
D.	1,2 and 3
Answer» C. 2 and 3

Discussion

235.	Booth's coding in 8 bits for the decimal number −57 is:
A.	0 – 100 + 1000
B.	0 – 100 + 100 – 1
C.	0 – 1 + 100 – 10 + 1
D.	00 – 10 + 100 – 1
Answer» C. 0 – 1 + 100 – 10 + 1

Discussion

236.	The literal count of a Boolean expression is the sum of the number of times each literal appears in the expression. For example, the literal count of (x y + x z) is 4. What are the minimum possible literal counts of the product – of – sum and sum – of – product representations respectively of the function given by the following karnaugh map? Here, x denotes “don’t care”.
A.	(11,9)
B.	(9,13)
C.	(9,10)
D.	(11,11)
Answer» D. (11,11)

Discussion

237.	Let A = 11111010 and B = 00001010 be two 8 – bit 2's complement numbers. Their product in 2's complement is
A.	11000100
B.	10011100
C.	10100101
D.	11010101
Answer» B. 10011100

Discussion

238.	What is the result of evaluating the following two expressions using three-digit floating point arithmetic with rounding?
A.	9.51 and 10.0 respectively
B.	10.0 and 9.51 respectively
C.	9.51 and 9.51 respectively
D.	10.0 and 10.0 respectively
Answer» B. 10.0 and 9.51 respectively

Discussion

239.	What are the essential prime implicants of the following Boolean functions?
A.	a'c and ac'
B.	a'c and b'c
C.	a'c only
D.	ac' and b'c
Answer» B. a'c and b'c

Discussion

240.	For interval arithmetic best rounding technique use is ………..
A.	Rounding to plus and minus infinity
B.	Rounding to zero
C.	Rounding to nearest
D.	None of these
Answer» B. Rounding to zero

Discussion

241.	Find the value of radix r, with the following equality is matached.
A.	8
B.	7
C.	10
D.	>2
Answer» E.

Discussion

242.	Booth′s algorithm is used in floating – point
A.	Addition
B.	Subtraction
C.	Multiplication
D.	Division
Answer» D. Division

Discussion

243.	Assume that the time required for the eight functional units, which operate in each of the eight cycles, are as follows.
A.	4.67
B.	4.375
C.	4.44
D.	4.285
Answer» C. 4.44

Discussion

244.	How many minimum 2-input nor gates are needed to realize A+BC?
A.	2
B.	3
C.	4
D.	5
Answer» C. 4

Discussion

245.	The min term expansion of f(P,Q,R) = PQ + QR̅ + PR̅ is
A.	m₂+m₄+m₆+m₁
B.	m₀+m₁+m₃+m₅
C.	m₀+m₁+m₆+m₁
D.	m₂+m₃+m₄+m₅
Answer» B. m₀+m₁+m₃+m₅

Discussion

246.	Consider an algebraic system (A,), where A is a set of all non-zero real numbers and is a binary operation defined by A* b = ab/4 then (G*) is a
A.	Monoid
B.	Semi group
C.	Group
D.	Abelian group
Answer» B. Semi group

Discussion

247.	How many Boolean functions are possible with 3 Boolean variables such that the number of min terms are either one or two?
A.	18
B.	8
C.	26
D.	36
Answer» E.

Discussion

248.	How many digits are required to represent 126 bit binary number in decimal?
A.	32 bits
B.	36 bits
C.	42 bits
D.	46 bits
Answer» D. 46 bits

Discussion

249.	Assuming all numbers are in 2’s complement representation, which of the following numbers is divisible by 11111011?
A.	11100111
B.	11100100
C.	11010111
D.	11011011
Answer» B. 11100100

Discussion

250.	A 32-bit address bus allows access to a memory of capability
A.	64 MB
B.	16 MB
C.	1 GB
D.	4 GB
Answer» E.

Discussion

Explore topic-wise MCQs in Graduate Aptitude Test (GATE).

Consider a relation geq which represents “greater than or equal to”, that is, (x,y) ∈ geq only if y >= x.create table geq( ib integer not null ub integer not null primary key 1b foreign key (ub) references geq on delete cascade )Which of the following is possible if a tuple (x,y) is deleted?

Suppose the adjacency relation of vertices in a graph is represented in a table Adj(X,Y). Which of the following queries cannot be expressed by a relational algebra expression of constant length?

The relation book (title, price) contains the titles and prices of different books. Assuming that no two books have the same price, what does the following SQL query list? select title from book as B where (select count(*) from book as T where T.price > B.price) < 5

Two transactions T₁ and T₂ are given as follows:

In strict two-phase locking protocol

Consider a schema R(A,B,C,D) and functional dependencies A->B and C->D. Then the decomposition of R into R1(AB) and R2(CD) is

Consider the relations r1(P, Q, R) and r2(R, S, T) with primary keys P and R respectively. The relation r1 contains 2000 tuples and r2 contains 2500 tuples. The maximum size of the join r1⋈ r2 is :

In SQL, relations can contain null values, and comparisons with null values are treated as unknown. Suppose all comparisons with a null value are treated as false. Which of the following pairs is not equivalent?

To prevent signals from colliding on the bus, ……………….. Prioritize access to memory by I/o channels and processors.

Halt operation comes under ………

What is the maximum number of different Boolean functions involving n boolean variables?

Consider the following subtraction and Identify the correct answer.

The register which keeps track of the execution of a program and which contains the memory address of the instruction currently being executed is known as …………

What is the control unit’s function in the CPU?

Find the radix 5 representation for the following decimal representation:

A 5 stage pipeline with the stages taking 1, 1, 3, 1, 1 units of time has a through put of

A 2 level memory has an average access time of 30 ns with cache and memory access time as 20 ns and 150 ns respectively. What is the hit ratio?

Consider a hypothetical k-map in which essential prime implicants covering all the min – terms except two. Each of the left over min – term is covered by 3 different redundant prime implicants. What would be the no of minimal expressions denoted by the map?

How many Boolean functions are possible with 2 trinary variables?

Which one is required while establishing the communication link between CPU and peripherals?

Which of the following holds data and processing instructions temporarily until the CPU needs it??

A computer system has 4k – word cache organized in a block – set-associative manner, with 4 blocks per set, 64 words per block, memory is word addressable. The number of bits in the SET and WORD fields of the main memory address format is

Which of the following is not involved in a memory write operation?

System calls are usually invoked by using

Define the connective * for the Boolean variable X and Y as :

(1217)₈ is equivalent to

…………… improve system performance by temporarily storing data during transfers s/w devices or processers that operate at different speeds.

Which of the following register processors used for fetch and execute operations?

Booth's coding in 8 bits for the decimal number −57 is:

Let A = 11111010 and B = 00001010 be two 8 – bit 2's complement numbers. Their product in 2's complement is

What is the result of evaluating the following two expressions using three-digit floating point arithmetic with rounding?

What are the essential prime implicants of the following Boolean functions?

For interval arithmetic best rounding technique use is ………..

Find the value of radix r, with the following equality is matached.

Booth′s algorithm is used in floating – point

Assume that the time required for the eight functional units, which operate in each of the eight cycles, are as follows.

How many minimum 2-input nor gates are needed to realize A+BC?

The min term expansion of f(P,Q,R) = PQ + QR̅ + PR̅ is

Consider an algebraic system (A,*), where A is a set of all non-zero real numbers and * is a binary operation defined by A* b = ab/4 then (G*) is a

How many Boolean functions are possible with 3 Boolean variables such that the number of min terms are either one or two?

How many digits are required to represent 126 bit binary number in decimal?

Assuming all numbers are in 2’s complement representation, which of the following numbers is divisible by 11111011?

A 32-bit address bus allows access to a memory of capability

Consider an algebraic system (A,), where A is a set of all non-zero real numbers and is a binary operation defined by A* b = ab/4 then (G*) is a