APPSC-2012-DL CA

Question 1

Which error detection method involves polynomials?

A
VRC
B
LRC
C
CRC
D
Checksum
       Computer-Networks       CRC
Question 1 Explanation: 
CRC error detection method involves polynomials.
The divisor in the CRC generator is most often represented not as a string of 1s and 0s, but as an algebraic polynomial. The polynomial format is used for it is short and it can be used to prove the concept mathematically. A string of 0s and 1s can be represented as a polynomial with coefficients of 0 and 1, where the power of each term in the polynomial indicates the position of the bit and the corresponding coefficient reflects the value of the bit (0 or 1).
Question 2

Which one from the following is memory of a volatile nature?

A
Flash
B
Masked ROM
C
DRAM
D
EPROM
       Computer-Organization       Types-of-Memory
Question 2 Explanation: 
Volatile memory is computer storage that only maintains its data while the device is powered.
Most RAM (random access memory) used for primary storage in personal computers is volatile memory. RAM is much faster to read from and write to than the other kinds of storage in a computer, such as the hard disk or removable media. However, the data in RAM stays there only while the computer is running; when the computer is shut off, RAM loses its data.
Question 3

For a Binomial distribution mean is always

A
greater than variance
B
less than variance
C
equal to variance
D
greater than or equal to variance
       Engineering-Mathematics       Probability
Question 3 Explanation: 
Mean = np
Variance = npq, where q=(1-p)
Logically we are multiplying some number q =1-p to mean to get variance and q belongs to [ 0,1]. so if we multiply a value less than 1 to np to get npq then
np>=npq.
Question 4

Which layer of OSI model is responsible for transmitting raw bit stream over on physical cable?

A
Presentation
B
Physical
C
Transport
D
Network
       Computer-Networks       ISO-OSI-layers
Question 4 Explanation: 
Physical layer is responsible for bit rate control over physical cable.
Question 5

Which one from the following is a true statement about Binary trees (BST)?

A
A BST is the Binary tree in which data in the nodes is ordered in a particular way.
B
The data in any nodes of right subtree of BST must be greater than or equal to the data in the given node.
C
A BST have worst case when the data is already in order.
D
All (1), (2) and (3).
       Data-Structures       Binary-Trees
Question 5 Explanation: 
1. In Binary search tree the right child of a node is greater than or equal to given node and left child of a node is less than the given node. So true.
2. True.
3. True, in this case the tree will be skewed.
Question 6

Which of the following is not a logical database structure?

A
Chain
B
Network
C
Tree
D
Relational
       Database-Management-System       Databases
Question 6 Explanation: 
Chain is not a logical database structure.
Question 7

Which layer of OSI model is responsible to translates logical network address and names to their physical address?

A
Session
B
Presentation
C
Data
D
Network
       Computer-Networks       ISO-OSI-layers
Question 7 Explanation: 
The Network layer protocol translates logical addresses to MAC addresses or physical addresses.
Question 8

The number of tuples in the result of a left outer join operation will always be

A
greater than the number of tuples in the result of the corresponding join operation.
B
at least equal to the number of tuples in the result of the corresponding join operation.
C
less than the number of tuples in the result of the corresponding join operation.
D
greater than the number of tuples in the result of the corresponding right outer join operation.
       Database-Management-System       Relational-Algebra
Question 8 Explanation: 
The number of tuples in the result of a left outer join operation will always be at least equal to the number of tuples in the result of the corresponding join operation, because if all the tuples of left relation is not included during join operation then the remaining tuples of left relation will also be included in the final output.
Question 9

If A and B are independent events then

A
P(A∪B) = P(A) + P(B) + (A∩B)
B
P(A∪B) = 0
C
P(A∪B) = P(A) + P(B) – (A∩B)
D
P(A∪B) = P(A) + P(B)
E
None of the above
       Engineering-Mathematics       Probability
Question 9 Explanation: 
If A and B are independent events then
P(A∩B) = P(A)P(B)
So finally we can say that,
P(AUB) = P(A) + P(B) - P(A∩B)
= P(A) + P(B) - P(A)P(B)
Question 10

A vertex of how many degree is isolated?

A
0
B
1
C
2
D
3
       Engineering-Mathematics       Graph-Theory
Question 10 Explanation: 
A vertex is isolated if and only if it is not connected to any other vertices. Means a vertex of degree zero is said to be isolated.
Question 11

Which network component is not associated at physical layer of OSI model?

A
Multiplexer
B
Hubs
C
Amplifier
D
Router
       Computer-Networks       ISO-OSI-layers
Question 11 Explanation: 
Router is associated with network layer and rest of the devices are associated with physical layer.
Question 12

A closed path with no other repeated vertices than the starting and ending vertices is known as

A
Steiner tree
B
Cycle
C
Complement graph
D
Spanning tree
       Engineering-Mathematics       Graph-Theory
Question 12 Explanation: 
A closed path with no other repeated vertices than the starting and ending vertices is called cycle.
Question 13

Which one from the following is a false statement about TCP/IP model?

A
Network Access layer performs encapsulation of IP datagrams into frames and mapping IP addresses to physical hardware addresses.
B
Transport layer has primary two protocols – TCP and UDP.
C
The Internet Layer is in between Network Access layer and Transport layer.
D
The IP is a primary protocol at Transport Layer.
       Computer-Networks       TCP/IP
Question 13 Explanation: 
Option 4 is wrong because TCP and UDP is a primary protocol at transport layer.
Question 14

Let the functional dependencies, (A → B, B → C) hold for relation P(A,B,C). If it is decomposed in R(A,B) and S(B,C), then the decomposition will be

A
Lossy
B
Lossless
C
Non-Lossless
D
Strongly
       Database-Management-System       Functional-Dependency
Question 14 Explanation: 
The decomposition is lossless because B is common attribute and is a key in relation S ,so the decomposition is lossless.
Question 15

Y = 4x2 is an equation of

A
Parabola
B
Circle
C
Hyperbola
D
Eclipse
       Engineering-Mathematics       Co-ordinate-Geometry
Question 15 Explanation: 
Y = 4x2 is an equation of parabola.
Question 16

To find the second highest salary from Employees table, which of the following query is true?

A
Select max (salary) from employees where salary = (select max (salary from employees where salary < (select max (salary) from employees);
B
Select min (salary) from (select salary from employees order by salary desc) where rownum ←2
C
Select max (salary) from employees where salary < (select max(salary from employees)
D
Select max (salary) from employees where salary = (select salary from employees where rownum = 2 order by salary)
       Database-Management-System       SQL
Question 16 Explanation: 
Select max (salary) from employees where salary < (select max(salary from employees) query gives the second highest salary from Employees table . The second query calculates the highest salary and then the first query selects the highest salary other than the already selected highest salary means the first query outputs the second highest salary.
Question 17

Which one from the following is a false statement about memory management?

A
Thrashing improves system performance.
B
Swapping increases system overhead.
C
Overhead is more in non-contiguous memory allocation compared to contiguous allocation.
D
Swapping is more effective in non-contiguous memory allocation.
       Operating-Systems       Memory-Management
Question 17 Explanation: 
Thrashing decreases the system performance because in thrashing there are more no. of page faults.
Question 18

Array is

A
A non linear data structure
B
A primitive data structure
C
A linear data structure
D
None from (1), (2), and (3)
       Data-Structures       Arrays
Question 18 Explanation: 
Array is a linear and non-primitive data structure.
Question 19

Consider following three statement about memory management
(I) Memory fragmentation results in poor utilization of memory.
(II) Memory fragmentation is the area of memory, which is allocated to a process but unused.
(III) Demand paging can increase the degree of multiprogramming.

A
Only (I) and (III)
B
Only (ii) and (III)
C
All (I), (II) and (III)
D
None from (I), (II) and (III)
       Operating-Systems       Memory-Management
Question 19 Explanation: 
Memory fragmentation is when most of your memory is allocated in a large number of non-contiguous blocks, or chunks - leaving a good percentage of your total memory unallocated, but unusable for most typical scenarios. This results in out of memory exceptions, or allocation errors (i.e. malloc returns null). Hence statement I and II is true.
Also demand paging increase the degree of multiprogramming. Hence statement III is also true.
Question 20

Which searching algorithm requires that all of the data must be in order?

A
Sequential search
B
Binary search
C
Linear search
D
All (1), (2), and (3)
       Algorithms       Searching
Question 20 Explanation: 
Binary search algorithm requires that all of the data must be in order.
Question 21

Which one from the following is a false statement about page replacement algorithm?

A
LRU page replacement algorithm uses the principle of locality of reference.
B
LRU page replacement algorithm does not posses the stack property.
C
Optimal page replacement algorithm is infeasible.
D
FIFO page replacement algorithm does not posses the stack property.
       Operating-Systems       Page-Replacement-algorithm
Question 21 Explanation: 
S1 is true.
S2 is false,because LRU page replacement algorithm possess the stack property.
S3 is true because Optimal page replacement is infeasible because the virtual memory handler does not have knowledge of the future reference. It is just used to evaluate the performance with other algorithms for comparison.
S4 is true thats why FIFO suffers from anomaly called belady's anamoly.
Question 22

Which one from the following is a false statement about Poisson distribution?

A
In Poisson distribution, the number of trials is infinite.
B
Poisson distribution is useful with discrete variable only.
C
Poisson distribution is for unequal probability in single trial.
D
None from the above (1), (2), and (3) is a false statement.
       Engineering-Mathematics       Probability
Question 22 Explanation: 
S1 is true. Poisson limit theorem states that if in a binomial distribution, the number of trials 'n' tends to infinity and the probability of success is small (close to 0), then the binomial distribution tends to poisson distribution.
S2 is true.
S3 is false because Poisson distribution is for unequal probability in multiple trial.
Question 23

Time complexity of Binary search is

A
O(n)
B
O(n2)
C
O(log n)
D
O(n log n)
       Algorithms       Searching
Question 23 Explanation: 
Time complexity of binary search is O(logn).
Question 24

If a surgeon transplants kidney in 250 cases and succeeds in 130 cases, then the probability of success after operation is

A
0.52
B
048
C
0
D
0.25
       Engineering-Mathematics       Probability
Question 24 Explanation: 
Required probability = 130/250 = 0.52
Question 25

Consider following two statements about I/O organization.
(I) An I/O port uses a flip-flop to implement memory cell.
(II) In DMA I/O peripheral device reads and writes memory without going through CPU.
Which one from the following is more appropriate?

A
Statement (I) is true while (II) is false.
B
Statement (II) is true while (I) is false.
C
Both statements (I) and (II) are true.
D
Both statements (I) and (II) are false.
       Computer-Organization       Data-transfer-modes
Question 25 Explanation: 
S1 is false. An I/O port typically uses a latch rather than a flip-flop to implement the memory cell.
S2 is true.
Question 26

Time complexity of Merge sort is

A
O(n)
B
O(n2)
C
O(log n)
D
O(n log n)
       Algorithms       Sorting
Question 26 Explanation: 
Time complexity of merge sort is O(nlogn).
Question 27

In which Disk scheduling algorithm starvation is possible?

A
FCFS
B
SCAN
C
Shortest Seek Time First (SSTF)
D
C-SCAN
       Operating-Systems       Process-Scheduling
Question 27 Explanation: 
In SSTF the request with largest seek time may suffer if a request of low seek time comes.
Question 28

In which sorting algorithm average number of comparison is (n2 – n) / 2?

A
Insertion sort
B
Selection sort
C
Merge sort
D
Quick sort
       Algorithms       Sorting
Question 28 Explanation: 
Insertion sort have average no. of comparisons (n2 – n) / 2.
Question 29

What should be the access time of cache memory in order to achieve 98% hit ratio, if the memory access time in 200ns and effective access time required is 20ns?

A
16ns
B
18ns
C
20ns
D
10ns
       Operating-Systems       Memory-Management
Question 29 Explanation: 
EMAT = 0.98 × Hit time of cache + 0.02 × (200 + Hit time of cache)
20 = 0.98 × H + 0.02 (200 + H)
20 = 0.98H + 0.02 × 200 + 0.02H
20 = 0.98H + 4 + 0.02H
16 = H
∴ Access time of cache memory = 16 ns
Question 30

Variance of binomial distribution is

A
p
B
np
C
q
D
npq
       Engineering-Mathematics       Probability
Question 30 Explanation: 
Variance of binomial distribution is npq and mean of binomial distribution is np.
Question 31

The Leaves of a tree

A
Are those nodes with single child.
B
Is the maximum length of a branch from the root to leaf.
C
Are those nodes with no children.
D
Are those nodes have same parent.
       Data-Structures       Trees
Question 31 Explanation: 
The leaves of a tree are those nodes with no children.
Question 32

Consider following three statements about Data Encryption Standard (DES).
(I) DES uses a 56 bit key to encrypt 64 bit data blocks.
(II) DES is a Block cipher.
(III) DES provides Cipher Block Chaining mode to overcome the problem of poor diffusion.
The false statement from above statements is/are

A
Only (I)
B
Only (I) and (III)
C
Only (III)
D
None from (I), (II) and (III)
       Computer-Networks       Network-Security
Question 32 Explanation: 
DES is a block cipher, and encrypts data in blocks of size of 64 bit each, means 64 bits of plain text goes as the input to DES, which produces 64 bits of cipher text. The same algorithm and key are used for encryption and decryption, with minor differences. The key length is 56 bits. The basic idea is show in figure.To overcome the problem of poor diffusion, DES provides a cipher block chaining (CBC) mode.
Hence all the statements are true.
Question 33

Consider following three statements above scheduler
(I) Dispatcher is a part of schedule responsible to select a new process whenever the current process yields the CPU.
(II) The medium term scheduler is responsible for swapping.
(III) The Long Term scheduler determines to whom CPU should be allocated from the ready queue.
The true statement from above statements is/are

A
All (I), (II), and (III)
B
Only (I) and (II)
C
Only (I) and (III)
D
Only (II) and (III)
       Operating-Systems       Process-State-Transition-Diagram
Question 33 Explanation: 
S1 is true.
S2 is true.
S3 is false, because the short term scheduler determines to whom CPU should be allocated from the ready queue.
Question 34

The number 105 in decimal system is equal to

A
(140)5
B
(410)5
C
(042)5
D
(321)5
       Digital-Logic-Design       Number-Systems
Question 34 Explanation: 

∴ Answer is (410)5
Question 35

While restarting recovery, which sequence is followed?

A
Undo transactions of undo-list; redo transactions of redo-list.
B
Reo transactions of redo-list; undo transactions of undo-list.
C
Undo transactions of undo-list.
D
Redo transactions of redo-list.
       Database-Management-System       Transactions
Question 35 Explanation: 
First we have to do UNDO list ==> system back to some consistence state, then we have to do REDO list.
Question 36

IP address range for E class network is

A
1.0.0.0 to 127.0.0.0
B
128.0.0.0 to 191.255.0.0
C
224.0.0 to 239.255.255.0
D
240.0.0.0 to 255.255.255
       Computer-Networks       IP-Address
Question 36 Explanation: 
IP addresses of class E ranges from 240.0. 0.0 – 255.255. 255.255.
Question 37

SQL injection consists of

A
Authorized Physicians injecting SQL in patients.
B
A mechanism to improve performance of database
C
A hacking mechanism enters the system by providing erroneous input.
D
Exception handling routines.
       Database-Management-System       SQL
Question 37 Explanation: 
SQL Injection
SQL injection is a code injection technique that might destroy your database.
SQL injection is one of the most common web hacking techniques.
SQL injection is the placement of malicious code in SQL statements, via web page input.
Question 38

If A, B, and C are subsets of U then the simplified form of the expression ~A∪~B∪(A∩B∩~C) using the law of set theory is

A
~A∩~B∩~C
B
~A∪~B∪~C
C
~A∪~B∪C
D
~A∩~B∪~C
       Engineering-Mathematics       Set-Theory
Question 38 Explanation: 
A’∪B’∪(A∩B∩C’)
In general we can write it as,
A’ + B’ + (ABC’)
= A’ + B’ + ABC’
= A’ + (B’ + B)(B’ + AC’)
= A’ + 1∙(B’ + AC’)
= A’ + B’ + AC’
= (A’ + A)(A’ + C’) + B’
= A’ + C’ + B’
= A’∪C’∪B’
= A’∪B’∪C’
Question 39

The C++ statement cout <<(0 ==0) will

A
Outputs as 0
B
Outputs as 1
C
Generate error at the time of compilation
D
Generate run time
       OOPS       C++
Question 39 Explanation: 
The above C++ statement outputs as 1.
Question 40

Project 802 defines standards for which layers of the OSI Models?

A
Application and Presentation layers
B
Physical and Data Link layers
C
Network and Data Link layers
D
Transport and Network layers
       Computer-Networks       ISO-OSI-layers
Question 40 Explanation: 
Project 802 defined a family of low-level protocol standards at physical and data link layers of the OSI model.
Question 41

Which scheduling algorithm from the following is allows processes to move from one queue (different classified queues based on scheduling parameters) to another?

A
Multilevel Queue Scheduling
B
Priority Based Scheduling
C
Round Robin Scheduling
D
Multilevel Feedback Queue Scheduling
       Operating-Systems       Process-Scheduling
Question 41 Explanation: 
Multilevel feedback queue scheduling solves the problem of starvation of low priority processes in multilevel scheduling and in this the processes can move from one queue to another.
Question 42

A multiprocessor computer architecture where two or more identical processor are connected to a single shared main memory is known as

A
Asymmetric Multiprocessing
B
Symmetric Multiprocessing
C
NUMA – Non Uniform Memory Access
D
Clustered Multiprocessing
Question 42 Explanation: 
A multiprocessor computer architecture where two or more identical processor are connected to a single shared main memory is known as symmetric multiprocessing.
Question 43

Which of the following statements is true about C++ language?

A
C++ supports multiple inheritance
B
C++ does not support operator overloading.
C
C++ supports dynamic polymorphism
D
C++ supports interface definitions.
E
Both A and D
       Programming-in-c++       Properties
Question 43 Explanation: 
C++ supports multiple inheritance.
C++ supports operator overloading.
C++ supports static polymorphism.
C++ supports interface definitions.
Question 44

Which one from the following is a false statements about deadlock?

A
Memory is a non-preemptible resource.
B
Mutual exclusion condition is not possible for several resources under deadlock prevention
C
Recovery from deadlock is possible through rollback
D
If there is a cycle and there is single instance per resource type then there is a deadlock.
       Operating-Systems       Deadlock
Question 44 Explanation: 
False,Memory is a preemptive resource.
True.
True.
True.
Question 45

Following are the conditions of deadlock
(I) Mutual exclusion
(II) Hold and Wait
(III) No preemption
(IV) Circular Wait
Which conditions from above are necessary conditions for deadlock?

A
Only (I), (II), and (III)
B
Only (II, (III) and (IV)
C
Only (I), (III) and (IV)
D
All (I), (II), (III) and (IV)
       Operating-Systems       Deadlock
Question 45 Explanation: 
The four necessary conditions for deadlock are:
Mutual exclusion
Hold and wait
No preemption
Circular wait
Question 46

In OSI model, data compression is carried out by

A
Network layer
B
Physical layer
C
Data Link layer
D
Presentation layer
       Computer-Networks       ISO-OSI-layers
Question 46 Explanation: 
Data compression and expansion is carried out by presentation layer.
Question 47

The age of a father is twice that of the elder son. After ten years the age of the father will be three times that of younger son. If the difference of ages of the two sons is 15 years then what will be the age of the father?

A
50
B
54
C
56
D
58
       Aptitude       Numerical
Question 47 Explanation: 
Let the age of elder son = E
The age of father = 2E
Let the age of younger son = Y
Then according to question,
2E + 1 = 3(Y + 10) --- (I)
and
E - Y = 15
Y = E - 15 ---(II)
Putting (II) in (I),
2E + 10 = 3(E - 15 + 10)
2E + 10 = 3(E - 5)
2E + 10 = 3E - 15
25 = E
∴ Age of father = 2E = 2 × 25 = 50
Question 48

For the sets A = {X∈R: -4 < X < 3} and B = x∈R: -1 < x < 7, the value of A∪B is

A
{x∈R: -1
B
{x∈R: -4
C
{x∈R: -4
D
{x∈R: -1
       Engineering-Mathematics       Set-Theory
Question 48 Explanation: 

So from above diagram, the union of two ranges will be,
-4 < x < 7
Question 49

Which of the following properties is implemented by concurrency control algorithms.

A
Durability
B
Consistency
C
Atomicity
D
Isolation
       Database-Management-System       Transactions
Question 49 Explanation: 
Concurrency control method is used to apply isolation through mutual exclusion between conflicting transactions.
Question 50

Consider the following ‘C’ language declaration in a[4] = {1,2,3,4}; What would be the output of the following

Printf(“%d”, *(a+2)+1); 
A
2
B
3
C
4
D
None of the above
       Programming       Arrays
Question 50 Explanation: 
*(a+2)+1 = a[2]+1 = 3+1 = 4
Question 51

Program Counter register contains address of the

A
Memory data
B
Next instruction to be executed by the CPU
C
Current instruction being executed by the CPU
D
Address (i,e. indirect address) of next instruction to be executed by the CPU
       Computer-Organization       Registers
Question 51 Explanation: 
Program counter contains the address of the next instruction to be executed by the CPU.
Question 52

Any “C” statement that beings with # is process by

A
Compiler
B
Linker
C
Preprocessor
D
Assembler
Question 52 Explanation: 
Any ‘C' statement that beings with # is process by preprocessor.
Question 53

Partial dependencies are removed to achieve which normal form?

A
First normal form
B
Second normal form
C
BCNF
D
Third normal form
       Database-Management-System       Normalization
Question 53 Explanation: 
In 2NF partial dependencies are not allowed. Hence partial dependencies are removed to achieve second normal form.
There are 53 questions to complete.