ISRO CS 2017 – May


Question 1
If A is a skew symmetric matrix, then At
A
diagonal matrix
B
A
C
-A
D
0
Linear Algebra    ISRO CS 2017 - May    
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Question 1 Explanation: 
If A is skew symmetric matrix then AT = -A
Question 2
If A and B be two arbitrary events, then
A
P(A ∩ B) = P(A)P(B)
B
P(A ∪ B) = P(A) + P(B)
C
P(A / B) = P(A ∩ B) + P(B)
D
P(A ∪ B) <= P(A) + P(B)
ISRO CS 2017 - May    
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Question 2 Explanation: 
Case:1 P(A ∪ B) = P(A) + P(B) - P (A ∩ B). Case:2 For two mutually exclusive events, (A ∩ B) = 0, So P(A ∪ B) <= P(A) + P(B) So, option (D) is correct.
Question 3
Using Newton-Raphson method, a root correct to 3 decimal places of the equation x3 - 3x - 5 = 0
A
2.222
B
2.275
C
2.279
D
None of the above
Numerical Methods and Calculus    ISRO CS 2017 - May    
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Question 4
What does the data dictionary identify?
A
Field names
B
Field formats
C
Field Types
D
All of these
Software Engineering    ISRO CS 2017 - May    
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Question 5
Which of the following concurrency control protocol ensures both conflict serializability and free from deadlock?
A
Time stamp ordering
B
2 Phase locking
C
Both (a) and (b)
D
None of the above
Transactions and concurrency control    ISRO CS 2017 - May    
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Question 5 Explanation: 
Both Time stamp ordering and 2 Phase locking protocol ensures conflict serializability but only Time stamp ordering protocol provides freedom from deadlock.
Question 6
ACID properties of a transactions are
A
Atomicity, consistency, isolation, database
B
Atomicity, consistency, isolation, durability
C
Atomicity, consistency, integrity, durability
D
Atomicity, consistency, integrity, database
Transactions and concurrency control    ISRO CS 2017 - May    
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Question 6 Explanation: 
Every transaction holds ACID properties. A: Atomicity: Either a transaction should be performed completely or it should rollback. C: Consistency: Every transaction specifies some consistency constraints and these constraints should follow even after transaction occurs. I: Isolation: Every transaction should be performed in isolation so that no other transaction can see the intermediate result of any transaction. D: Durability: Every transaction performed should be recorded and despite all the failures these records must persist.
Question 7
What is the output of the following SQL query?
select count(*) from ((select Employee, Department from Overtime_allowance) as S
natural join (select Department, OT_allowance from Overtime_allowance) as T);
A
16
B
4
C
8
D
None of the above
E
none
SQL    ISRO CS 2017 - May    
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Question 7 Explanation: 
(select Employee, Department from Overtime_allowance) as S natural join (select Department, OT_allowance from Overtime_allowance) as T)
Table S                          Table R
Employee     Department          Department     OT_allowance
Rama         Mechanical          Mechanical     5000
Gopi         Electrical          Electrical     2000
Sindhu       Computer            Computer       4000
Mahesh       Civil               Civil          1500
Now when we apply a natural join on S and R, it matches the common attribute Department in both the tables and outputs the common tuples. So, 4 tuples will be given as the output. Correct option (B)
Question 8
Which symbol denote derived attributes in ER Model?
A
Double ellipse
B
Dashed ellipse
C
Squared ellipse
D
Ellipse with attribute name underlined
ER and Relational Models    ISRO CS 2017 - May    
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Question 8 Explanation: 
Refer:Database Management System | ER Model Correct option (B)
Question 9
The symmetric difference of sets A = {1, 2, 3, 4, 5, 6, 7, 8} and B = {1, 3, 5, 6, 7, 8, 9} is
A
{1, 3, 5, 6, 7, 8}
B
{2, 4, 9}
C
{2, 4}
D
{1, 2, 3, 4, 5, 6, 7, 8, 9}
Set Theory & Algebra    ISRO CS 2017 - May    
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Question 9 Explanation: 
Symmetrical Difference of A and B = (A - B) ∪ (B - A) (A - B) = {2, 8} (B - A) = {9} (A - B) ∪ ( B - A) = {2, 8} ∪ {9} = {2, 8, 9}
Question 10
The problems 3-SAT and 2-SAT are
A
Both NP-complete
B
Both in P
C
NP-complete and in P, respectively
D
Undecidable and NP-complete, respectively
NP Complete    ISRO CS 2017 - May    
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Question 10 Explanation: 
3-SAT problem is NP- complete problem whereas 2- SAT problem is P- class problem. Refer: 2-Satisfiability (2-SAT) Problem Option (C) is correct.
There are 79 questions to complete.


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