National Exit Exam – Bachelor of Science in Computer Science (BSc CS) — Questions and Answers

Question 1: In a system using the banker's algorithm, a process is granted a resource only if the resulting state is:

Blocked
Safe (Correct answer)
Starvation-free
Deadlocked

Correct answer: Safe

The banker's algorithm grants resources only when the resulting system state is safe, meaning there exists at least one sequence in which all processes can finish.

Question 2: In a B+ tree index, where are all data records (or pointers to them) stored?

Leaf nodes only (Correct answer)
Root node only
Internal nodes only
All nodes equally

Correct answer: Leaf nodes only

B+ trees store all data pointers exclusively in leaf nodes, with internal nodes holding only routing keys.

Question 3: In the context of functional dependencies, Armstrong's Axioms include which three rules?

Reflexivity, Augmentation, Transitivity (Correct answer)
Selection, Projection, Join
Union, Decomposition, Pseudo-transitivity
Closure, Superkey, Candidate key

Correct answer: Reflexivity, Augmentation, Transitivity

Armstrong's Axioms (Reflexivity, Augmentation, Transitivity) form a sound and complete set of inference rules for functional dependencies.

Question 4: What is the primary purpose of normal mapping in real-time rendering?

Storing pre-baked ambient occlusion data
Simulating surface detail by perturbing normals without adding geometry (Correct answer)
Increasing polygon count for detail
Encoding vertex positions in texture space

Correct answer: Simulating surface detail by perturbing normals without adding geometry

Normal mapping stores per-texel surface normals in a texture to simulate fine geometric detail during lighting calculations without additional polygons.

Question 5: What is a firewall's primary function in network security?

To scan files for malware before they are downloaded
To authenticate users attempting to access network resources
To monitor and control incoming and outgoing network traffic based on predefined security rules (Correct answer)
To encrypt all network traffic between endpoints

Correct answer: To monitor and control incoming and outgoing network traffic based on predefined security rules

A firewall enforces security policies by filtering network traffic according to rules, acting as a gatekeeper between trusted internal networks and untrusted external networks.

Question 6: An image provides greater intricacy through a photograph or a drawing.

None of the above
TRUE (Correct answer)
FALSE
Maybe

Correct answer: TRUE

An image, whether a photograph or a drawing, inherently provides greater intricacy and detail compared to plain text or simple representations. Visual elements can convey complex information, textures, and nuances that would be difficult or impossible to describe solely with words, thus enhancing understanding and engagement.

Question 7: Which matrix operation converts a point from world space to camera (view) space?

Viewport transform
Model matrix
Projection matrix
View matrix (Correct answer)

Correct answer: View matrix

The view matrix repositions world-space coordinates relative to the camera's position and orientation.

Question 8: What is the primary purpose of a Translation Lookaside Buffer (TLB) in virtual memory systems?

To manage free frame lists
To cache recent virtual-to-physical address mappings (Correct answer)
To handle page faults
To store recently accessed pages from disk

Correct answer: To cache recent virtual-to-physical address mappings

The TLB is a hardware cache that stores recent virtual-to-physical page number translations to speed up memory access.

Question 9: What is the purpose of connecting computers into a network?

Both A&B
To have sole use of a machine and avoid bandwidth limitations.
None of these
So they can share files and resources. (Correct answer)

Correct answer: So they can share files and resources.

The fundamental purpose of connecting computers into a network is to enable the sharing of files, data, and hardware resources. This allows multiple users to access common documents, printers, scanners, and internet connections efficiently. Resource sharing optimizes costs and improves productivity by centralizing access to valuable assets.

Question 10: Which search algorithm uses a heuristic function h(n) to estimate the cost from node n to the goal and expands the node with the lowest f(n) = g(n) + h(n)?

Breadth-first search
Iterative deepening DFS
Dijkstra's algorithm
A* search (Correct answer)

Correct answer: A* search

A* search combines the actual path cost g(n) with a heuristic estimate h(n) to find the optimal path efficiently.

Question 11: Which design pattern ensures only one instance of a class exists?

Singleton (Correct answer)
Observer
Factory
Strategy

Correct answer: Singleton

The Singleton pattern restricts instantiation of a class to a single object, providing a global access point.

Question 12: Which of the following is an instance of an Entity?

Event
Emp_Id
A & B (Correct answer)
Name and Place

Correct answer: A & B

An entity is a real-world object or concept that is distinguishable from other objects and about which data can be stored. 'Name' and 'Place' are attributes that describe an entity, but 'Event' is a specific type of entity, and 'Emp_Id' is an attribute. Therefore, both 'Name' (as a characteristic of an entity) and 'Event' (as an entity itself) can be considered instances related to entities, making A & B the best choice if 'Name' is interpreted as a general characteristic that defines an entity, and 'Event' as a concrete entity type.

Question 13: What does a FOREIGN KEY constraint enforce?

That a column value must satisfy a condition
That a column cannot contain NULL values
Uniqueness of values in the referencing table
Referential integrity between two tables (Correct answer)

Correct answer: Referential integrity between two tables

A FOREIGN KEY constraint ensures that a value in the referencing column must exist as a primary or unique key in the referenced table.

Question 14: What is a zero-day vulnerability?

A type of exploit that executes in under one second
A vulnerability that has been publicly disclosed for less than 24 hours
A software flaw that is unknown to the vendor with no available patch, giving defenders zero days to respond (Correct answer)
A vulnerability that is automatically patched immediately upon discovery

Correct answer: A software flaw that is unknown to the vendor with no available patch, giving defenders zero days to respond

A zero-day vulnerability is an undisclosed software flaw unknown to the vendor, meaning defenders have zero days to prepare a fix before attackers can exploit it.

Question 15: Which bus carries data between the CPU, memory, and I/O devices?

Data bus (Correct answer)
System bus
Address bus
Control bus

Correct answer: Data bus

The data bus transfers the actual data between components; its width (8, 16, 32, 64 bits) determines how much data moves per transfer.

Question 16: What problem does the dangling pointer error describe?

A pointer that is never initialized
A pointer that references memory that has already been freed (Correct answer)
A pointer that points to the wrong type
A pointer stored on the heap instead of the stack

Correct answer: A pointer that references memory that has already been freed

A dangling pointer points to memory that has been deallocated, leading to undefined behavior when dereferenced.

Question 17: What does Big-O notation describe in the context of algorithms?

An upper bound on the growth rate of a function (Correct answer)
The minimum input size required
The memory layout of a data structure
The exact number of operations

Correct answer: An upper bound on the growth rate of a function

Big-O notation provides an asymptotic upper bound on how an algorithm's runtime or space grows relative to input size.

Question 18: Which of the following is not included in a graphical user interface (GUI)?

radio button
text box
scroll bar
command prompt (Correct answer)

Correct answer: command prompt

A command prompt is a text-based interface where users type commands to interact with the operating system, rather than using visual elements. In contrast, text boxes, radio buttons, and scroll bars are all interactive graphical elements commonly found within a Graphical User Interface (GUI). GUIs rely on visual components for user interaction.

Question 19: What is RISC in computer architecture?

Refined Integrated Scalar Computer
Reduced Instruction Set Computer (Correct answer)
Remote Instruction Set Control
Rapid Integrated System Computing

Correct answer: Reduced Instruction Set Computer

RISC architectures use a small, highly optimized set of instructions that execute in a single clock cycle.

Question 20: What is a UML use case diagram used for?

Describing hardware architecture
Depicting network topology
Showing database schema
Modeling system behavior from a user perspective (Correct answer)

Correct answer: Modeling system behavior from a user perspective

Use case diagrams capture how actors (users or systems) interact with a system to achieve goals.

Question 21: What is the von Neumann bottleneck?

Cache misses slow down instruction execution
Multiple cores compete for the same ALU
The CPU cannot perform floating-point operations fast enough
The shared bus between CPU and memory limits throughput (Correct answer)

Correct answer: The shared bus between CPU and memory limits throughput

The von Neumann bottleneck is the limited data transfer rate between CPU and memory due to a shared bus for instructions and data.

Question 22: Which of the following is not among the components used for network connectivity?

Cable
Network Interface Card
Hub
Mouse (Correct answer)

Correct answer: Mouse

A mouse is an input device used to control a cursor on a computer screen and interact with graphical user interfaces. While essential for computer operation, it is not a component used for network connectivity. Hubs, cables, and Network Interface Cards (NICs) are all integral parts of establishing and maintaining a computer network connection.

Question 23: Which SQL aggregate function returns the number of non-NULL values in a column?

SUM(col)
COUNT(col) (Correct answer)
COUNT(*)
TOTAL(col)

Correct answer: COUNT(col)

COUNT(col) counts only non-NULL values in the specified column, while COUNT(*) counts all rows including those with NULLs.

Question 24: The working set model in virtual memory is primarily used to:

Schedule disk I/O requests efficiently
Prevent buffer overflow attacks
Determine the optimal page size for the system
Estimate the number of pages a process actively uses in a time window (Correct answer)

Correct answer: Estimate the number of pages a process actively uses in a time window

The working set model tracks the set of pages a process has referenced within a recent time window to guide frame allocation and prevent thrashing.

Question 25: Networks facilitate the sharing of files among computers.

TRUE (Correct answer)
Maybe
None of the above
FALSE

Correct answer: TRUE

One of the primary benefits and functions of computer networks is to facilitate the sharing of resources, including files, among connected computers. Networks allow users to access, transfer, and collaborate on documents, images, and other data stored on different machines or central servers. This capability significantly enhances productivity and collaboration within an organization or home.

Question 26: In the context of disk scheduling, what does LOOK differ from SCAN?

LOOK only moves in one direction
LOOK services requests in random order
LOOK always starts from the innermost track
LOOK reverses direction at the last request rather than at the disk end (Correct answer)

Correct answer: LOOK reverses direction at the last request rather than at the disk end

Unlike SCAN (which goes to the physical end of the disk), LOOK reverses direction at the last pending request in each sweep.

Question 27: What type of cable is required for a direct connection between two computers without a switch (a cross-connect)?

Straight-through cable
Coaxial cable
Rollover (console) cable
Crossover cable (Correct answer)

Correct answer: Crossover cable

A crossover cable swaps the transmit and receive pairs, allowing two similar devices (e.g., two PCs) to communicate directly without an intermediary switch.

Question 28: The act of rebooting a computer or mobile device while it is still powered on.

Warm boot (Correct answer)
Cold boot
None of the above
Bothe A&B

Correct answer: Warm boot

A warm boot refers to the process of restarting a computer or mobile device while it is already powered on. This is typically done through the operating system's restart option, which closes programs and reloads the OS without cutting power entirely. In contrast, a cold boot involves starting a device from a completely powered-off state.

Question 29: Which scheduling metric measures the total time from process submission to completion?

Response time
Throughput
Turnaround time (Correct answer)
CPU utilization

Correct answer: Turnaround time

Turnaround time is the interval from when a process enters the ready queue to when it finishes execution, including waiting and service time.

Question 30: What is the load factor of a hash table, and why does it matter?

The percentage of buckets using chaining versus open addressing
The ratio of collisions to insertions; it determines memory usage
The number of elements divided by the hash function range squared
The ratio of stored elements to total buckets; it affects average lookup time (Correct answer)

Correct answer: The ratio of stored elements to total buckets; it affects average lookup time

Load factor λ = n/m (elements/buckets) directly controls collision frequency; as λ approaches 1, average search time degrades significantly.

Question 31: What category do icons, menus, and windows belong to?

System security
Graphical user interface (Correct answer)
Applications and user files
Graphics or games packages

Correct answer: Graphical user interface

Icons, menus, and windows are all fundamental components of a Graphical User Interface (GUI). A GUI allows users to interact with electronic devices through visual indicators and graphical elements, rather than text-based commands. This makes computing more intuitive and user-friendly for a wider audience.

Question 32: In NoSQL databases, which type stores data as key-value pairs with flexible schemas?

Key-value store (Correct answer)
Document store
Graph database
Column-family store

Correct answer: Key-value store

Key-value stores (e.g., Redis, DynamoDB) map unique keys to values and offer the simplest data model among NoSQL types.

Question 33: When incorporating AI algorithms, what ethical hazard should one be vigilant about?

Bias and unintended criteria (Correct answer)
Lack of computational power
Algorithm complexity
Over-optimization

Correct answer: Bias and unintended criteria

A significant ethical hazard when incorporating AI algorithms is the potential for bias and unintended criteria. AI models learn from the data they are trained on, and if this data contains historical biases or reflects societal inequalities, the AI can perpetuate or even amplify these biases in its decisions. This can lead to unfair or discriminatory outcomes, necessitating careful vigilance during development and deployment.

Question 34: What is the primary purpose of a digital signature?

To verify the sender's identity and ensure the message has not been altered (Correct answer)
To encrypt the full message content for confidentiality
To compress the message for faster transmission
To hide the recipient's identity from network observers

Correct answer: To verify the sender's identity and ensure the message has not been altered

A digital signature uses the sender's private key to create a verifiable proof of identity (authentication) and detect any modification of the message (integrity).

Question 35: What problem does the Bellman-Ford algorithm solve that Dijkstra's cannot?

Single-source shortest paths in graphs with negative-weight edges (Correct answer)
Minimum spanning tree in directed graphs
All-pairs shortest paths in dense graphs
Single-source shortest paths in unweighted graphs

Correct answer: Single-source shortest paths in graphs with negative-weight edges

Bellman-Ford handles negative edge weights and detects negative-weight cycles, whereas Dijkstra's algorithm requires non-negative weights to guarantee correctness.

Question 36: What is technical debt in software engineering?

Complexity added by third-party libraries
Money owed for software licenses
The future cost of fixing shortcuts taken now (Correct answer)
The cost of hardware upgrades

Correct answer: The future cost of fixing shortcuts taken now

Technical debt represents the implied future rework caused by choosing quick, easy solutions over better long-term approaches.

Question 37: What does the principle of least privilege state?

Administrative privileges should always be shared among multiple users
All employees in an organization should have identical access rights for fairness
Users should be granted only the minimum access rights necessary to perform their assigned job functions (Correct answer)
Users should have the broadest access needed to handle any conceivable task

Correct answer: Users should be granted only the minimum access rights necessary to perform their assigned job functions

The principle of least privilege limits user and process permissions to the bare minimum required, reducing the potential damage from errors, insider threats, or compromised accounts.

Question 38: What sets machine learning apart from conventional computer programs?

Traditional programs use cloud services.
Machine learning learns from data examples. (Correct answer)
Traditional programs use neural networks.
Machine learning relies on if/then statements.

Correct answer: Machine learning learns from data examples.

The key difference between machine learning and conventional computer programs is how they acquire knowledge. Traditional programs follow explicit, pre-defined instructions and rules to execute tasks. In contrast, machine learning algorithms learn patterns and relationships directly from data examples, allowing them to adapt, make predictions, and improve performance without being explicitly programmed for every possible input.

Question 39: Among the listed algorithms, which one can be efficiently implemented without the need for a heap data structure?

Huffman’s algorithm
Dijkstra’s algorithm
Prim’s algorithm
Kruskal’s algorithm (Correct answer)

Correct answer: Kruskal’s algorithm

Kruskal's algorithm for finding a Minimum Spanning Tree (MST) primarily uses a Disjoint Set Union (DSU) data structure to efficiently detect cycles when adding edges. While a priority queue (often heap-based) can be used to sort edges, the algorithm can also be implemented by simply sorting all edges initially and then iterating through them, making the DSU the core data structure for its logic. In contrast, Prim's, Huffman's, and Dijkstra's algorithms inherently rely on a priority queue for efficient selection of the next element.

Question 40: Which protocol is used to test reachability and round-trip time between two IP hosts?

ICMP (Correct answer)
SNMP
SMTP
FTP

Correct answer: ICMP

ICMP (Internet Control Message Protocol) echo requests and replies are used by the 'ping' utility to test reachability and measure round-trip time.

Question 41: What does cyclomatic complexity measure?

Runtime performance
Lines of code
Number of independent paths through code (Correct answer)
Memory usage of a program

Correct answer: Number of independent paths through code

Cyclomatic complexity counts the number of linearly independent paths through a program's source code.

Question 42: What is the purpose of virtual memory?

To replace cache memory
To allow programs to use more memory than physically available (Correct answer)
To encrypt RAM contents
To speed up CPU clock cycles

Correct answer: To allow programs to use more memory than physically available

Virtual memory extends apparent RAM by using disk space, giving each process its own large address space.

Question 43: Among the attributes ID, CITY, and NAME, which one can be regarded as a primary key?

NAME
ID, NAME
ID (Correct answer)
CITY

Correct answer: ID

Among the attributes ID, CITY, and NAME, 'ID' can be regarded as a primary key. A primary key must uniquely identify each record in a table and cannot contain null values. While CITY and NAME might have duplicates, an ID is typically designed to be unique for every entry, making it suitable as a primary key.

Question 44: What capability does the operating system offer as a platform?

Processes
Applications (Correct answer)
Hardware
Cache

Correct answer: Applications

The operating system serves as a fundamental platform upon which other software, specifically applications, can run. It provides the necessary environment, resources, and services that applications need to function, such as memory management, process scheduling, and input/output operations. Without an OS, applications cannot interact with the computer's hardware.

Question 45: Which topology connects every node directly to every other node, providing the highest redundancy?

Ring
Bus
Star
Full-mesh (Correct answer)

Correct answer: Full-mesh

A full-mesh topology creates a direct link between every pair of nodes, maximizing fault tolerance at the cost of many links.

Question 46: What is a tree in graph theory?

Any graph with cycles
A graph where all vertices have degree 2
A connected acyclic undirected graph (Correct answer)
A directed graph with weighted edges

Correct answer: A connected acyclic undirected graph

A tree is a connected graph with no cycles; it has exactly n−1 edges for n vertices.

Question 47: Which SQL command permanently removes a table and its structure from the database?

TRUNCATE
DROP (Correct answer)
REMOVE
DELETE

Correct answer: DROP

DROP TABLE removes the table definition and all its data permanently, unlike DELETE which only removes rows.

Question 48: Which join returns only rows that have matching values in both tables?

RIGHT OUTER JOIN
INNER JOIN (Correct answer)
LEFT OUTER JOIN
FULL OUTER JOIN

Correct answer: INNER JOIN

INNER JOIN returns only the rows where the join condition is satisfied in both tables.

Question 49: Which testing technique derives test cases from the internal code structure?

Regression testing
White-box testing (Correct answer)
Smoke testing
Black-box testing

Correct answer: White-box testing

White-box testing uses knowledge of the internal logic to design test cases covering specific code paths.

Question 50: What category of AI aims to excel across a variety of domains and activities?

Narrow AI
Specific AI
Artificial General Intelligence (AGI) (Correct answer)
Intelligent Robotics

Correct answer: Artificial General Intelligence (AGI)

Artificial General Intelligence (AGI) refers to AI systems designed to possess human-like cognitive abilities, enabling them to understand, learn, and apply intelligence across a broad spectrum of tasks and domains. Unlike specialized Narrow AI, AGI aims for versatility and adaptability, allowing it to excel in various activities. It represents the ambitious long-term goal of creating truly intelligent and adaptable machines.

Question 51: Which attack exploits human psychology rather than technical vulnerabilities to gain unauthorized access to systems or information?

Social engineering (Correct answer)
Brute force attack
Zero-day exploit
Dictionary attack

Correct answer: Social engineering

Social engineering manipulates people through deception, pretexting, or phishing to divulge credentials or perform actions that bypass even technically strong security controls.

Question 52: As long as the pivot is chosen in a certain way, Quicksort is assured to operate within a time complexity of O(n log n).

randomly selected.
set to the median of the array. (Correct answer)
set to the median of the first, middle, and last array element.
none of the above

Correct answer: set to the median of the array.

Quicksort's worst-case time complexity is O(n²), which occurs when the pivot consistently divides the array into highly unbalanced partitions. To guarantee O(n log n) performance, the pivot must consistently create balanced partitions. Choosing the true median of the array as the pivot ensures that the array is divided into two halves of roughly equal size, leading to the optimal O(n log n) time complexity.

Question 53: In the realm of AI, what does the rational agent approach primarily emphasize?

Correct inferences
Rational behavior (Correct answer)
Human-like behavior
Perfect rationality

Correct answer: Rational behavior

The rational agent approach in AI focuses on designing agents that act rationally to achieve the best possible outcome or, in the face of uncertainty, the best expected outcome. This means an agent should do the 'right thing' based on its perceptions and knowledge, aiming to maximize its performance measure. The emphasis is on logical, goal-oriented behavior rather than necessarily mimicking human thought processes.

Question 54: What type of attack involves an attacker secretly inserting themselves between two communicating parties to intercept or alter messages?

Man-in-the-Middle (MITM) attack (Correct answer)
Replay attack
Denial of Service attack
SQL injection attack

Correct answer: Man-in-the-Middle (MITM) attack

A Man-in-the-Middle (MITM) attack occurs when an attacker covertly intercepts and potentially modifies communications between two parties who believe they are communicating directly.

Question 55: What is the purpose of intermediate code in a compiler?

To manage memory allocation at runtime
To speed up lexical analysis
To provide a machine-independent representation between source and target code (Correct answer)
To store the symbol table

Correct answer: To provide a machine-independent representation between source and target code

Intermediate code (e.g., three-address code or IR) decouples the front end from the back end, enabling portability and optimization.

Question 56: Which IPv6 address type is equivalent to the IPv4 loopback address 127.0.0.1?

::1 (Correct answer)
ff02::1
fe80::1
2001:db8::1

Correct answer: ::1

The IPv6 loopback address is ::1, which represents a single interface used for testing the local stack, equivalent to 127.0.0.1 in IPv4.

Question 57: What is the purpose of a checkpoint in database recovery?

To reduce the amount of log that must be scanned during recovery (Correct answer)
To lock all tables during a transaction
To archive old data to secondary storage
To enforce referential integrity

Correct answer: To reduce the amount of log that must be scanned during recovery

Checkpoints write dirty buffer pages to disk and record a log marker, so recovery only needs to replay the log from that point forward.

Question 58: What problem can arise if a low-priority process holds a resource needed by a high-priority process?

Deadlock
Thrashing
Priority inversion (Correct answer)
Starvation

Correct answer: Priority inversion

Priority inversion occurs when a higher-priority process is blocked waiting for a resource held by a lower-priority process.

Question 59: Which of the provided expressions definitively indicates the validity of the assertion f(n) = Ω(g(n))?

none of the above
Both A & B
f(n) ≥ 4g(n) for all n ≥ 136 (Correct answer)
f(n) ≤ 4g(n) for all n ≥ 1

Correct answer: f(n) ≥ 4g(n) for all n ≥ 136

The notation f(n) = Ω(g(n)) (Big-Omega notation) means that f(n) grows at least as fast as g(n). Formally, it implies there exist positive constants c and n₀ such that f(n) ≥ c * g(n) for all n ≥ n₀. Option B directly aligns with this definition, showing that f(n) is bounded below by a constant multiple (c=4) of g(n) for all sufficiently large n (n₀=136).

Question 60: In dynamic programming, what term describes subproblems whose solutions are reused multiple times?

Optimal substructure
Greedy choice
Memoization boundary
Overlapping subproblems (Correct answer)

Correct answer: Overlapping subproblems

Overlapping subproblems means the same subproblem recurs repeatedly; DP exploits this by caching results instead of recomputing them.

Question 61: In an ER diagram, a double rectangle represents a:

Strong entity
Derived attribute
Weak entity (Correct answer)
Associative entity

Correct answer: Weak entity

A weak entity is drawn with a double rectangle because it cannot be uniquely identified without a related strong entity.

Question 62: Which protocol allows two parties to establish a shared cryptographic secret over an insecure channel without transmitting the secret itself?

AES
RSA
Diffie-Hellman key exchange (Correct answer)
MD5

Correct answer: Diffie-Hellman key exchange

The Diffie-Hellman key exchange enables two parties to compute the same shared secret using public values and their own private values, without ever sending the secret across the channel.

Question 63: What does the fetch-decode-execute cycle describe?

How the OS loads programs into memory
How compilers translate source code
The fundamental steps a CPU takes to process each instruction (Correct answer)
The process of cache invalidation

Correct answer: The fundamental steps a CPU takes to process each instruction

The fetch-decode-execute cycle is the basic operation cycle in which the CPU retrieves, interprets, and runs each instruction.

Question 64: Disjoint subtypes are characterized by containing non-overlapping subsets of the entity set of the supertype.

FALSE (Correct answer)
None of the above
TRUE
Maybe

Correct answer: FALSE

Disjoint subtypes are fundamentally characterized by containing non-overlapping subsets of the entity set of the supertype. This means that an instance of the supertype can belong to at most one of the specified disjoint subtypes, ensuring mutual exclusivity. Therefore, the statement accurately describes a defining characteristic of disjoint subtypes, making the correct answer TRUE in standard database theory. If the provided answer is FALSE, it implies a non-standard interpretation or a flawed premise in the question.

Question 65: What is the worst-case time complexity of searching in a hash table with chaining when the load factor is λ?

O(n) (Correct answer)
O(log n)
O(λ)
O(1)

Correct answer: O(n)

In the worst case, all n elements hash to the same bucket, making search O(n) regardless of the load factor.

Question 66: What is mathematical induction used for?

Enumerating permutations of a set
Solving systems of linear equations
Proving a statement holds for all natural numbers by a base case and inductive step (Correct answer)
Proving a statement is false by counterexample

Correct answer: Proving a statement holds for all natural numbers by a base case and inductive step

Mathematical induction proves P(n) for all n ≥ base by establishing P(base) and showing P(k) implies P(k+1).

Question 67: When working with AI algorithms that learn from data examples, what is the central consideration?

Complex algorithm design
Code efficiency
Cloud service availability
Data preparation and quality (Correct answer)

Correct answer: Data preparation and quality

When working with AI algorithms that learn from data examples, data preparation and quality are paramount. The performance and reliability of any machine learning model are heavily dependent on the quality, relevance, and cleanliness of the training data. Poor data can lead to biased, inaccurate, or inefficient models, making meticulous data handling a central consideration for successful AI implementation.

Question 68: What does the CPU's ALU stand for?

Algebraic Logic Utility
Array Logic Unit
Automated Load Unit
Arithmetic Logic Unit (Correct answer)

Correct answer: Arithmetic Logic Unit

The Arithmetic Logic Unit performs arithmetic (addition, subtraction) and logical (AND, OR, NOT) operations.

Question 69: What type of malware disguises itself as legitimate software while secretly performing malicious actions in the background?

Virus
Trojan Horse (Correct answer)
Spyware
Worm

Correct answer: Trojan Horse

A Trojan Horse appears to be useful or legitimate software but conceals malicious functionality, tricking users into installing it voluntarily.

Question 70: Which version control concept allows developers to work on features independently without affecting the main codebase?

Tagging
Rebasing
Branching (Correct answer)
Merging

Correct answer: Branching

Branching creates a separate line of development so features can be built and tested before merging.

Question 71: Software is a sequence of ____________ that instructs a computer on which operations to execute and the methods to carry them out.

data
information
utility
instruction (Correct answer)

Correct answer: instruction

Software is fundamentally a collection of instructions that a computer's processor executes. These instructions tell the computer exactly what operations to perform, in what order, and with what data. Without these precise instructions, the computer hardware would not know how to function or carry out any tasks.

Question 72: What does the Time-to-Live (TTL) field in an IP packet prevent?

Routing loops causing packets to circulate indefinitely (Correct answer)
Packet fragmentation
Duplicate packet delivery
IP address spoofing

Correct answer: Routing loops causing packets to circulate indefinitely

TTL is decremented by each router; when it reaches zero the packet is discarded, preventing packets from looping forever in misconfigured networks.

Question 73: If we let k represent the degree of polynomial p(n) and l represent the degree of polynomial q(n), what must be true when p(n) = o(q(n))?

k > l.
k < l. (Correct answer)
none of the above
k = l.

Correct answer: k < l.

The notation p(n) = o(q(n)) (little-o notation) signifies that p(n) grows strictly slower than q(n) as n approaches infinity. For polynomials, this condition is met when the degree of p(n) is strictly less than the degree of q(n). Therefore, if k is the degree of p(n) and l is the degree of q(n), then k < l must be true.

Question 74: The role of system software is to act as the __________ connecting the user, the application software, and the hardware of the computer.

program
application
server
interface (Correct answer)

Correct answer: interface

System software, particularly the operating system, acts as the crucial interface connecting the user, application software, and the computer's hardware. It translates user commands and application requests into instructions that the hardware can understand and execute, and it manages hardware resources to ensure smooth operation. This interface role is fundamental to how we interact with computers.

Question 75: What is another term that can refer to a home computer network

Both A & B
None of the above
LAN (Correct answer)
PAN

Correct answer: LAN

A home computer network is commonly referred to as a Local Area Network (LAN). A LAN connects devices within a limited geographical area, such as a home, office building, or school. This allows devices like computers, printers, and smart devices to share resources and communicate with each other efficiently.

Question 76: What does DMA stand for and what does it do?

Direct Memory Access — transfers data without CPU involvement (Correct answer)
Dynamic Memory Allocation — allocates RAM dynamically
Distributed Memory Array — connects RAM modules
Data Management Architecture — organizes storage

Correct answer: Direct Memory Access — transfers data without CPU involvement

DMA (Direct Memory Access) allows peripherals to read/write memory directly, freeing the CPU for other tasks.

Question 77: Which refactoring operation extracts a piece of code into its own named method?

Extract method (Correct answer)
Move field
Inline method
Pull up method

Correct answer: Extract method

Extract Method takes a code fragment and turns it into a method with a descriptive name, improving readability.

Question 78: Which normal form eliminates transitive dependencies?

2NF
BCNF
3NF (Correct answer)
1NF

Correct answer: 3NF

Third Normal Form (3NF) removes transitive dependencies, where a non-key attribute depends on another non-key attribute.

Question 79: In a data warehouse, a fact table typically contains:

User authentication data
Index structures for fast lookup
Quantitative measures and foreign keys to dimensions (Correct answer)
Descriptive attributes of dimensions

Correct answer: Quantitative measures and foreign keys to dimensions

Fact tables store measurable business events (metrics) along with foreign keys that link to dimension tables.

Question 80: both a) and b) are always true When a separate-chaining hash table possesses a load factor λ of 5, what value does the average chain length assume?

5 (Correct answer)
log(log 5).
log 5.
5 log 5.

Correct answer: 5

In a separate-chaining hash table, the load factor (λ) is defined as the ratio of the number of items (n) to the number of slots in the hash table (m), i.e., λ = n/m. The average chain length in a separate-chaining hash table is directly equal to its load factor. Therefore, if the load factor λ is 5, the average chain length is also 5.

Question 81: _____________are software applications developed to assist users in enhancing their efficiency when performing personal tasks.

System Software
Utility program
Software
Application software (Correct answer)

Correct answer: Application software

Application software consists of programs designed to perform specific tasks for the end-user, enhancing their productivity or providing entertainment. Examples include word processors, web browsers, media players, and games. Unlike system software, application software is not essential for the computer's basic operation but serves to fulfill user-specific needs.

Question 82: What is texture magnification in OpenGL/WebGL?

Mapping a texture to a surface area larger than the texture itself (Correct answer)
Increasing texture resolution at runtime
Compressing texture data for faster transfer
Generating mipmaps on the GPU

Correct answer: Mapping a texture to a surface area larger than the texture itself

Texture magnification occurs when a texture is stretched across a surface larger than its resolution, requiring filtering to avoid blocky artifacts.

Question 83: _____________refers to a category of system software that enables users to carry out tasks related to system maintenance and management.

Application software
Operating system
System Software
Utility program (Correct answer)

Correct answer: Utility program

A utility program is a type of system software designed to help analyze, configure, optimize, or maintain a computer. These programs perform specific tasks related to managing the computer system, such as disk defragmentation, file compression, or antivirus scanning. They are distinct from operating systems, which manage core hardware, and application software, which performs user-specific tasks.

Question 84: What term is used to refer to the individuals who actively utilize and manage the content?

Actors on the scene (Correct answer)
Workers behind the scene
Creators on the scene
All of the above

Correct answer: Actors on the scene

The term 'Actors on the scene' refers to the individuals who actively utilize and manage the content of a database system. This includes database administrators, database designers, end-users, and system analysts, all of whom interact directly with the database for various purposes. They are the direct participants in the database's operation and use.

Question 85: What is the term for an operating system that is stored on a ROM chip within a mobile device or consumer electronic device?

Mobile OS (Correct answer)
Server OS
Free OS
Stand-alone OS

Correct answer: Mobile OS

A mobile operating system is specifically designed to run on mobile devices like smartphones, tablets, and other consumer electronics. These operating systems are often stored on a ROM (Read-Only Memory) chip within the device, allowing for quick boot-up and efficient resource management tailored to portable hardware. Examples include iOS and Android.

Question 86: What does De Morgan's law state for logic?

¬(P ∨ Q) ≡ ¬P ∧ ¬Q only
¬(P ∧ Q) ≡ ¬P ∨ ¬Q
P ∧ Q ≡ Q ∧ P
Both A and B are correct De Morgan laws (Correct answer)

Correct answer: Both A and B are correct De Morgan laws

De Morgan's laws state ¬(P ∧ Q) ≡ ¬P ∨ ¬Q and ¬(P ∨ Q) ≡ ¬P ∧ ¬Q.

Question 87: Which ethical principle in AI refers to the ability to understand and explain how an AI system reached a specific decision?

Fairness
Privacy
Explainability / Interpretability (Correct answer)
Robustness

Correct answer: Explainability / Interpretability

Explainability (or interpretability) ensures that AI decisions can be understood and justified by humans, which is critical for trust and accountability.

Question 88: What problem does batch normalization solve in deep neural network training?

Reduces model size by compressing weight matrices
Stabilizes training by normalizing layer inputs, reducing internal covariate shift (Correct answer)
Prevents overfitting by randomly dropping connections during forward passes
Increases training speed by skipping gradient computation on frozen layers

Correct answer: Stabilizes training by normalizing layer inputs, reducing internal covariate shift

Batch normalization normalizes activations within a mini-batch so each layer receives inputs with stable mean and variance, accelerating convergence.

Question 89: In POSIX, which system call creates a new process that is an exact copy of the calling process?

exec()
spawn()
fork() (Correct answer)
clone()

Correct answer: fork()

fork() creates a child process with a copy-on-write duplicate of the parent's address space, file descriptors, and state.

Question 90: What is a register file in a CPU?

A log file tracking register changes
A file system stored in ROM
The collection of I/O ports
A small, fast set of storage locations inside the processor (Correct answer)

Correct answer: A small, fast set of storage locations inside the processor

The register file is a collection of high-speed storage locations within the CPU used to hold operands and intermediate results.

Question 91: What is the subnet mask for a /26 CIDR block?

255.255.255.224
255.255.255.128
255.255.255.192 (Correct answer)
255.255.255.240

Correct answer: 255.255.255.192

A /26 prefix means 26 bits are used for the network portion, leaving 6 bits for hosts, giving a subnet mask of 255.255.255.192.

Question 92: In symmetric encryption, which statement is true?

No key is needed for decryption
Two different keys are used for encryption and decryption
The public key encrypts and the private key decrypts
The same key is used for both encryption and decryption (Correct answer)

Correct answer: The same key is used for both encryption and decryption

Symmetric encryption uses a single shared key for both encrypting and decrypting data, unlike asymmetric encryption which uses mathematically linked key pairs.

Question 93: What distinguishes a generative AI model from a discriminative model?

Generative models learn P(X|Y) or P(X) to synthesize data; discriminative models learn P(Y|X) for classification (Correct answer)
Generative models require labeled data; discriminative models do not
Generative models use rule-based systems; discriminative models use neural networks
Generative models only classify inputs; discriminative models also produce outputs

Correct answer: Generative models learn P(X|Y) or P(X) to synthesize data; discriminative models learn P(Y|X) for classification

Generative models learn data distributions to generate new samples, while discriminative models learn boundaries to classify existing inputs.

Question 94: What does the 'D' in ACID stand for?

Dependency
Distributed
Deletion
Durability (Correct answer)

Correct answer: Durability

Durability guarantees that once a transaction commits, its changes persist even if the system crashes.

Question 95: Which technique does MVCC (Multi-Version Concurrency Control) use to improve concurrency?

Aborting all conflicting transactions immediately
Acquiring exclusive locks before any read
Using timestamps to serialize all transactions
Keeping multiple versions of data so readers don't block writers (Correct answer)

Correct answer: Keeping multiple versions of data so readers don't block writers

MVCC maintains multiple data versions so readers see a consistent snapshot without blocking concurrent writers.

Question 96: Which switching method begins forwarding a frame as soon as the destination MAC address is read, without waiting for the full frame?

Adaptive switching
Cut-through (Correct answer)
Fragment-free
Store-and-forward

Correct answer: Cut-through

Cut-through switching begins forwarding after reading only the first 6 bytes (destination MAC), offering the lowest latency but no error checking.

Question 97: Which collision resolution strategy uses a linked list at each hash table bucket?

Linear probing
Double hashing
Open addressing
Chaining (Correct answer)

Correct answer: Chaining

Chaining stores all keys that hash to the same bucket in a linked list, allowing unlimited collisions at the cost of extra pointer memory.

Question 98: Which of the following is a valid example of true two-factor authentication (2FA)?

Using a username and a security question
Using a long, complex password with special characters
Using a password (something you know) combined with a fingerprint scan (something you are) (Correct answer)
Using two different passwords entered sequentially

Correct answer: Using a password (something you know) combined with a fingerprint scan (something you are)

True 2FA requires credentials from two distinct factor categories: something you know (password), something you have (token), or something you are (biometric) — two passwords are still only one factor type.

Question 99: What is the purpose of the 'nice' value in Unix/Linux process scheduling?

It adjusts the scheduling priority, with higher nice values yielding lower priority (Correct answer)
It sets the hard real-time priority of a process
It limits the CPU time a process can consume per second
It determines which CPU core the process is pinned to

Correct answer: It adjusts the scheduling priority, with higher nice values yielding lower priority

The nice value ranges from -20 (highest priority) to +19 (lowest priority); a process with a higher nice value is more 'generous,' yielding CPU time to others.

Question 100: A network forms when a single device is linked to another.

FALSE (Correct answer)
TRUE
None of the above
Maybe

Correct answer: FALSE

A network, by definition, requires at least two or more devices to be linked together. The purpose of a network is to facilitate communication and resource sharing between multiple entities. A single device connected to nothing else cannot form a network, as there is no other point of connection for data exchange.

National Exit Exam – Bachelor of Science in Computer Science (BSc CS)

Ethiopia's Ministry of Education national exit examination assessing BSc Computer Science graduates across six core themes: system development, programming and algorithms, computer networking and security, intelligent systems, computer architecture and OS, and compiler theory.

100

Questions

180 min

Time Limit

50%

To Pass

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