2015 Ethiopian computer science exit exam model question

THIS PAGE CONTAINS 2015 ETHIOPIAN UNIVERSITY EXIT EXAM MODEL QUESTION OF COMPUTER SCIENCE DEPARTMENT

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1 Which one of the following file permissions enable a user to change the content of file or create/delete files in directory?

A Read(r)
B Execute(x)
C Write(w)
D A and B
Answer C

2 Which is a service that allows administrators to log in to a host from a remote location and control the host.

A DNS
B Telnet
C DHCP
D FTP
Answer B

3 Which directory contains binaries used by both system admin and non-privileged users?

A /etc
B /bin
C /mnt
D /lib
Answer B

4 What DHCP message is sent by the client to reply by broadcasting an acceptance message, requesting to lease IP information?

A. DHCPDISCOVER
B. DHCPOFFER
C. DHCPREQUEST
D. DHCPRELEASE
ANSWER: C

5 It is a command which can be used to troubleshoot name resolution issues and to verify the current status of the name servers?

A. ipconfig
B. nslookup
C. netstat
D. ipconfig
ANSWER: B

6 Which linux command can be used to see the status of DHCP server configuration?

A. Sudo systemctl restart isc-dhcp-server.service
B. Sudo systemctl status isc-dhcp-server.service.
C. Sudo apt install isc-dhcp-server
> D. Sudo nano etc/dhcp/dhcpd.conf
ANSWER: B

7 Assume you've been hired as a security engineer at company A, and you've recently installed a biometric authentication system. Unfortunately, the biometric system rejects a large number of legitimate, registered users. So, as a security engineer, how do you tune the system?

A. Increase the number of false rejections.
B. Reduce the number of false rejections.
C. Increase the False Acceptance Rate
D. Reduce the number of false acceptances.
ANSWER: B

8 Smart card is a good form of two-factor authentication because?

A. It contains a certificate on a microchip that is resistant to cloning or cracking

B. It can double as a proximity card for building entrance key card systems
C. It does not rely on internal power like a token
D. A smart card is portable and can be loaned to others
ANSWER: A

9 During your lunch break, your phone begins to receive unsolicited messages. What might this be an example of?

A. Packet sniffing
B. Bluesnarfing
C. Bluejacking
D. Spoofing
ANSWER: C

10 Which one of the following is true statement?

A. Active attack is an attack in which the attacker observes interaction with the system B. Passive attack is an attack in which the attacker directly interacts with the system
C. Unintentional attack is an attack where there is a deliberate goal of misuse
D. Ignoring notifications to install new updates and security patches is an unintentional attack
ANSWER: D

A network station transmits hundreds of SYN packets to a destination computer. What is the computer doing that sends the message?

A. Sending the contents of a large file to the destination computer
B. Attempting to establish a TCP connection with the destination computer
C. Attacking the destination computer with a SYN flood
D. Transmitting streaming audio or video to the destination computer
ANSWER: C

11 Alice and Bob decided to use public key cryptography to exchange messages. If Alice wants to send an encrypted message to Bob, which one is appropriate to transmit the encrypted message?

A. Alice encrypts the message using the Bob’s public key, and Bob decrypts the message using his private key.

B. Alice encrypts the message using the Bob’s public key, and Bob decrypts the message using his public key.

C. Alice encrypts the message using the Bob’s private key, and Bob decrypts the message using his private key.

D. Alice encrypts the message using the Bob’s public key, and Bob decrypts the message using Alice’s public key.
ANSWER: A

12 What CSS define in HTML?

A. How to save HTML elements
B. How to display HTML elements
C. How to send HTML elements
D. How to made HTML elements
ANSWER: B

13 Which of the following is not a benefit of using self-signed SSL certificates?

A. Cost reduction
B. Very easy to create
C. Authentication of the server
D. More sophisticated to crack
ANSWER: C

What two things do you need to create Webpages & view them?
A. text editor and a web browser

B. text editor and a compiler
C. compiler and a web browser
D. All of the above
ANSWER: A

14 Where in an HTML document is the correct place to refer to an external style sheet?

A. In the section
B. At the top of the document
C. In the section
D. At the end of the document
ANSWER: A

15 The _____ character tells browsers to stop tagging the text.

A. ?
B. /
C. >
D. %
ANSWER: B

16 What does an HTML tag do?

A. It specifies formatting and layout instructions for your web page.
B. It hides programming instructions from view.
C. It determines the organizational structure of your Web site.
D. It connects your web site to an operating environment.
ANSWER: A

17 Which of the following is not the scope of Variable in PHP?

A. Local
B. Global
C. Static
D. Extern
ANSWER: D

18 Which of following is not a Superglobals in PHP?

A. $_SERVER
B. $_ENV
C. $_FILES
D. $_PUT
ANSWER: D

19 A function in PHP which starts with __ (double underscore) is known as __________?

A.Inbuilt Function
B. Default Function
C. Magic Function
D. User Defined Function
ANSWER: C

20 Which of the following PHP functions accepts any number of parameters?

A. func_get_args()
B. func_get_argv()
C. get_argv()
D. get_argc()
ANSWER: A

21 Artificial intelligence is?

A. The embodiment of human intellectual capabilities within a computer.
B. a set of computer programs that produce output that would be considered to reflect intelligence if it were generated by humans
C. The study of mental faculties with mental models implemented on a computer.
D. All
ANSWER: D

22 Which one of the following is an attribute of AI systems?

A. Intelligence character
B. Natural/biological character
C. Sadness and happiness
D. Emotion and propensity
ANSWER: A

23 AI attempts not only the factual knowledge of a human but also the knowledge that relates to the judgmental or common sense part of the knowledge. What is the term used for describing the bold sentence?

A. Heuristic knowledge
B. Factual knowledge
C. procedural knowledge
D. Explicit knowledge
ANSWER: A

24 In __________ perspective of AI, the Turing test was developed as a technique for determining whether a computer could or could not demonstrate artificial Intelligence?

A. Thinking like humans
B. Acting like humans
C. Thinking rationally
D. Acting rationally
ANSWER: B

25 Which list is correct about the simplest case environment for the agent?

A. partially observable, stochastic, sequential, dynamic, continuous, multi-agent
B. partially observable, stochastic, episodic, dynamic, continuous, multi-agent
C. partially observable, stochastic, sequential, dynamic, discrete, multi-agent
D. Fully observable, Deterministic, Episodic, Static, Discrete, Single agent
ANSWER: D

26 It is try to solve problem by using stored information to draw new conclusions.

A. Automated reasoning
B. Natural language processing
C. Robotics
D. None of the above
ANSWER: A

27 Which one of the following is not correct about the evolution of Artificial intelligence?

A. Shifts from declarative to procedural programming paradigm
B. Simulate the human mind and learning behavior
C. Shift from general-purpose to domain-specific systems
D. None of the above
ANSWER: A

28 In a___________ relationship, one device controls traffic and the others must transmit through it.

A. Peer-to-peer
B. Point-to-point
C. Primary-secondary
D. full duplex
ANSWER: C

29 Which one of the following is different from the other?

A. 172.16.35.12
B. 188.17.12.14
C. 130.17.12.24
D. 126.17.12.254
ANSWER: A

30 It is a networking technique that enables us to transfer two or more different data signals simultaneously on the same communication channel.

A. Switching
B. Layering Task
C. Multiplexing
D. None
ANSWER: C

31 What is the prefix length notation for the subnet mask 255.255.255.248?

A. /30
B. /27
C. /28
D. /29
ANSWER:D

32 The wireless LAN specification is defined by IEEE, called, _______which covers the data link and physical layer.

A. IEEEE 802.2
B. IEEE 802.11
C. IEEE 802.3
D. IEEE 802.5
ANSWER: B

33 A network where there is no resource reservation is called?

A. Circuit-Switched Networks
B. message-switched networks
C. Packet-switched networks
D. Satellite network
ANSWER: C

34 Software is defined as ___________?

A. set of programs, documentation & configuration of data
B. set of programs
C. documentation and configuration of data
D. None of the mentioned
ANSWER: A

35 At Conceptual level Class diagrams should include?

A. operations only
B. attributes only
C. both operations and attributes
D. none of the mentioned
ANSWER: B

36 Constraints can be represented in UML by?

A. {text}
B. [text].
C. Constraint
D. None of the mentioned
ANSWER: A

37 What is an object?

A. An object is an instance of a class
B. An object includes encapsulation of data
C. An object is not an instance of a class
D. All of the mentioned
ANSWER: A

38 Which of the following statement(s) is true about interaction diagrams?

A. Interaction diagrams are at their best when they deal with one main design flow and not multiple variants that can happen
B. Interaction diagrams are good at designing part or all of one use case’s functionality across multiple objects
C. Interaction diagrams allow the analyst to show iteration and conditional execution for messaging between objects
D. All of the mentioned
ANSWER: D

39 UML interfaces are used to.

A. specify required services for types of objects
B. program in Java, but not in C++ or Smalltalk
C. define executable logic to reuse across classes
D. define an API for all classes
ANSWER: A

40 Which is not true about the object-oriented approach?

A. Emphasis is on data rather than procedure
B. Data is hidden and cannot be accessed by external functions
C. Objects communicate through Method
D. It supports abstract data but not the classD
ANSWER: D

41 Which of the following feature is also known as run-time binding or late binding?

A. Static binding
B. Dynamic loading
C. Dynamic binding
D. Data hiding
ANSWER: C

42 What happens if non static members are used in static member Method?

A. Executes fine
B. Compile time error
C. Executes if that member function is not used
D. Runtime error
ANSWER: B

43 What is encapsulation in OOP?

A. It is a way of combining various data members and member functions that operate on those data members into a single unit
B. It is a way of combining various data members and member functions into a single unit which can operate on any data
C. It is a way of combining various data members into a single unit
D. It is a way of combining various member functions into a single unit
ANSWER: B

44 Which is the correct syntax of inheritance?

A. class base_classname extends derived_classname{ /*define class body*/ }
B. class derived_classname extends base_classname{ /*define class body*/ }
C. class derived_classname base_classname{ /*define class body*/ }
D. class base_classname derived_classname{ /*define class body*/ }
ANSWER: A

45 Which of the following best describes member function overriding?

A. Member functions having the same name in derived class only
B. Member functions having the same name and different signature inside main function
C. Member functions having the same name and signature in base and derived classes
D. Member functions having the same name in base class only
ANSWER: C

46 Among the given options choose correct one?I. Von Neumann Architecture shares common memory for instructions and data.II. Harvard Architecture has separate memory for instruction and data?

A. Only I is true
B. I and II are true
C. Only II is true
D. I and II are false
ANSWER: B

47 Suppose we want to compute the value y6, √y, y1/3 using the value of y. which of the following among Flynn’s CPU classification will be best suited for above calculation?

A. SISD Stream
B. SIMD Stream
C. MISD Stream
D. MIMD Stream
ANSWER: C

48 In computers, subtraction is generally carried out by?

A. 9’s complement
B. 1’s complement
C. 2’s complement
D. 10’s complement
ANSWER: C

49 Which of the following best characterize a computer that uses memory-mapped I/O?

A. the computer provides special Instruction for manipulating the I/O port
B. I/O ports are placed at addresses on bus and are accessed just like other memory location
C. to perform an I/O operation, it is sufficient to place the data in an address and call the channel to perform the operation
D. ports are reference only by memory-mapped Instruction of the computer and are located hard-wired memory location
ANSWER: B

50 Suppose, after analyzing a new cache design, you discover that the cache has far too many conflict misses, and this needs to be resolved. You know that you must increase associativity in order to decrease the number of cache misses. What are the implications of increasing associativity?

A. Slower cache access time
B. Increase index bits
C. Increase block size
D. All of these
ANSWER: A

51 The pipelining process is also called as ______?

A. Superscalar operation
B. Assembly line operation
C. Von Neumann cycle
D. None of the mentioned
ANSWER: A

52 Computer programming is the process of performing a particular computation, usually by designing/ building an executable computer is?

A. Code
B. Program
C. File
D. All of the above
E. None of the above
ANSWER: D

53 The source of a program is written in one or more languages is directly executed by?

A. Arithmetic and logic unit
B. Central processing unit
C. Main Storage
D. None of the above
ANSWER: B

54 Which of the following is true about automatic and static variable?

A. Static variables initialization can be executed only once during the first call
B. If static variables are not initialized explicitly, it will be initialized to 0 automatically
C. If local variables are static, their values remain in case the function is called again
D. Automatic variables contents will be erased when the function ends
E. All
F. All excepts A
ANSWER: E

55 Functions are overloaded if?

A. if two or more functions differ only in their return types
B. if the number of arguments passed is different.
C. if the type of arguments passed is different.
D. if the number and/or type of arguments passed is different.
E. if the type of arguments passed is different and return type is different
F. All
G. All except A
ANSWER: G

56 Which keyword is used by method to refer to the object that invoked it?

A. This
B. Catch
C. Abstract
D. Import
ANSWER: A

57 Which of the following method of class String is used to obtain length of String object in Java?

A. length()
B. Sizeof()
C. lengthof()
D. limitof()
ANSWER: A

58 An algorithm is made up of two independent time complexities f (n) and g (n). Then the complexities of the algorithm is in the order of.

A. f(n) x g(n)
B.Max ( f(n),g(n))
B.Min (f(n),g(n))
C.f(n) + g(n)
D.None
ANSWER: B

59 A characteristic of the data that binary search uses but the linear search ignores is the?

A. Order of the elements of the list.
B. Length of the list. Maximum value in list.
C. Type of elements of the list
D. None
ANSWER: B

60 Assuming worst case analysis, which one of the following algorithm has a time complexity function of O(n3)?

A. An algorithm that determines whether a number is even or odd
B. An algorithm that adds two nXn matrices
C. An algorithm that finds an element in a sorted array using binary search method
D. An algorithm that multiplies two nXn matrices
E. An algorithm that finds an element in an unsorted array of elements using sequential method
ANSWER: D

61 Let the following array circular queue can accommodate maximum ten elements with the following data. front = 3 rear = 7 queue = ___, ____, ___, I, J,K,L ,M___, ___ . What will happen after performing Dequeue operation?

A) front = 2, rear = 6 and queue = ___, ____, H, I, J,k,l ___, ___ ,____
B) front = 4, rear = 7, queue = ___, __, __,___, J,K,L,M___, ___
C) front = 4, rear = 8 and queue = ___, ___, __ I, J, K, L,M,N___
D) front = 2 , rear = 5 and queue = ___, ____, H, I, J,k, ___, ___, ___ ,____
E) None
ANSWER: B

62 What would be the time complexity to add a node in a queue, if the first node pointing with front pointer and last nod pointing with rear Pointer?

A. O(1)
B. O(n)
C. O(n2)
D. θ(logn
ANSWER: A

63 Which one of the following is not the main purposes of an operating system?

A. To provide an environment for a computer user to execute programs on computer hardware in a convenient and efficient manner.
B. To allocate the separate resources of the computer as needed to solve the problemgiven.
C. Supervision of the execution of user programs to prevent errors and improper use of the computer,
D. Management of the operation and control of I/O devices
E. None
ANSWER: E

64 Which one of the following is not true about multiprogramming?

A. It makes efficient use of the CPU by overlapping the demands for the CPU and its I/O devices from various users
B. Special support from processor is essential
C. Execute more jobs in the same time
D. They are techniques used to increase system productivity.
ANSWER: B

64 Enforcing protection between different processes and providing new functionality that is not supported directly by underlying hardware are the two services and functions provided by an operating system. Which one of the following is not necessarily true related to the above services?

A. Processes are allowed to access only those memory locations that are associated with their address spaces.
B. Processes are not allowed to corrupt files associated with other users.
C. A process is also not allowed to access devices directly without operating system intervention.
D. Virtual memory and file systems are examples of new services provided by an operating system.
E. None of the above
ANSWER: A

65 What is a system call?

A. Is a way program requests a service from the kernel of the operating system.
B. It's an interface to an operating system that have a direct access to the operating system kernel.
C. It is a way of a user/ user-mode interact to the kernel mode.
D. A&C
E. All
ANSWER: E

66 A process which is copied from main memory to secondary memory on the basis of requirement is known as.

A. Demand Paging
B. Paging
C. Threads
D. Segmentation
ANSWER: A

67 Long-term scheduler is?

A. It selects which process has to be executed next and allocates CPU
B. It selects which process has to be brought into the ready queue
C. Both A & B
D. It selects which process to remove from memory by swapping
E. None of the mentioned
ANSWER: A

68 The total running time of heap sort is____ ?

A. O(N)
B. O(N log N)
C. O(log N)
D. O(N2)
ANSWER: B

69 Which one of the following is true about binary heap tree?

A. The height of a complete binary heap tree is O (n).
B. Parents' element values are always smaller than those of their children are maximum heap.
C. The maximum number of node for heap tree of height 2 is 8
D. None
ANSWER: D

70 Consider the following recurrence relation T(n)= T(n-1)+n for n>1, T(0)= 0, T(1)= 1. So, what is the time taken for nth iteration?

A. O(n)
B. O(n2)
C. O(logn)
D. O(nlogn)
ANSWER: B

71 In Huffman coding, data in a tree always stored at the _____________of the tree?

A. Roots
B. Leaves
C. left sub trees
D. right sub trees
ANSWER: B

72 Which one of the following is back tracking algorithm?

A. Huffman coding
B. Dijkstra algorithm
C. Prim’s algorithm
D. Depth first search algorithm
ANSWER: D

73 Which one of the following is needed to design Greedy algorithms and from which a solution set is created.

A. Solution set
B. Candidate set
C. Feasibility function
D. selection function
ANSWER: B

Which of the following are Limitations of Syntax Analyzers?

A. it cannot determine if a token is valid
B. it cannot determine if a token is declared before it is being used
C. it cannot determine if an operation performed on a token type is valid or not
D. All of the above
ANSWER: D

74 What is true about Syntax Directed Definitions?

A. Syntax Directed Definitions + Semantic rules = CFG
B. Syntax Directed Definitions + CFG = Semantic rules
C. CFG + Semantic rules = Syntax Directed Definitions
D. None of the above
ANSWER: C

75 The Grammar of the programming language is checked at _______ phase of compiler.

A. Semantic analysis
B. Syntax analysis
C. Code optimization
D. Lexical analysis
ANSWER:B

76 The regular expression: r+ = ______ ?

A. rr*
B. r*r
C. rr*r
D. A & B
ANSWER: D

77 The context free grammar is ambiguous if ___________?

A. The grammar contains non-terminals
B. No unique selection of the parse tree for a sentence
C. Production has two non-terminals side by side
D. None of the mentioned
ANSWER: B

78 Which of the following regular expression is equivalent to (a*+b)*?

A. (a+ab)*
B. (b*a+a*b)*
C. (ba+ab)*
D. All are equivalent
ANSWER: B

79 The language that cannot accept PDA?

A. Regular Language
B. Context Free Language
C. Context Sensitive Language
D. None of the above
ANSWER: C

80 Which of the following is more expressive and complex?

A. Regular Expression
B. Non-Deterministic Finite State Automata
C. Context Free Grammar
D. Push Down Automata
ANSWER: D

81 Which of the following is useless variable from the above production?

A. S and A
B. A and B
C. B and C
D. A and C
ANSWER: C

82 A push down automaton employs ________ data structure.

A. Queue
B. Linked List
C. Hash Table
D. Stack
ANSWER: D

83 A context free grammar G is in Chomsky normal form if every production is of the form.

A. A → BC or A → A
B. A → BC or A → a
C. A → BCa or B → b
D. None of these
ANSWER: A

84 Give a production grammar for the language L = {x/x ∈ (a, b)* , the number of a’s in x is a multiple of 3} .

A. {S → bS, S → b, S → aA, S → bA, A → aB, B → bB, B → aS, S → a}
B. {S → aS, S → bA, A → bB, B → bBa, B → bB}
C. {S → aaS, S → bbA, A → bB, B → ba}
D. None of these
ANSWER: B

85 The weak entity relationship set is represented in E-R diagram as?

A. Double diamonds
B. Double rectangle
C. Dashed lines
D. Diamond
ANSWER: A

86 In the __________ normal form, a composite attribute is converted to individual attributes?

A. First
B. Second
C. Third
D. Fourth
ANSWER: A

87 Is an attribute which can be further to be divide?

A. Composite
B. Null
C. Derived
D. Multiple value
ANSWER: A

88 A functional dependency is a relationship between or among?

A. Tables
B. Rows
C. Relations
D. Attributes
ANSWER: D

89 The entity set person is classified as student and employee. This process is called?

A. Generalization
B. Specialization
C. Inheritance
D. Constraint generalization
ANSWER: B

90 Describes no attribute of a primary key can be null?

A. Domain Integrity
B. Entity Integrity
C. Referential Integrity
D. Enterprise Integrity
ANSWER: B

91 Which of the following statement is not true?

A. The larger the lock granularity used; the more concurrency is reduced
B. Row-level locking maximizes concurrency
C. System overhead is increased in row-level locking
D. Degree of concurrency is low for fine granularity and high for coarse granularity
ANSWER: D

92 Databases threats that are related to unauthorized disclosure are called__________?

A. Loss of integrity
B. Loss of availability
C. Loss of confidentiality
D. None
ANSWER: C

93 Which of these statements about serializable schedules is true?

A. Every serializable schedule contains no conflicting actions
B. Every serializable schedule is recoverable
C. Every 2PL schedule is serializable
D. None of the above
ANSWER: C

94 Concurrency problem that occurs when one transaction is allowed to see the intermediate results of another transaction before it has committed, which will be failed for some reason is called _____?

A. Incorrect summery Problem
B. Lost update problem
C. Dirty Read Problem
D. All
E. None
ANSWER: C

95 The purpose of database recovery is________?

A. To bring the database into the last consistent state
B. To preserve consistency of transactions
C. To preserve durability property of transactions
D. All
E. None
ANSWER: D

96 Which of these statements about recoverable schedules is true?

A. In a recoverable schedule, if a transaction T commits, then any other transaction that Tread from must also have committed
B. Every recoverable schedule is serializable
C. In a recoverable schedule, no transaction will ever be aborted because a transaction that it read from has aborted
D. None of the above
ANSWER: D