Computer Science

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Exam Questions

What an Algorithm Is (Step-by-Step Instructions)New Algorithm vs Program (Same Idea, Different Thing)New Decomposition: Breaking a Problem into Sub-ProblemsNew Abstraction: Removing Unnecessary DetailNew A Systematic Approach to Solving ProblemsNew Writing Algorithms in PseudocodeNew Representing Algorithms with FlowchartsNew Representing Algorithms with Program CodeNew Inputs, Processes and Outputs in an AlgorithmNew Spotting Inputs, Processes and Outputs in Given PseudocodeNew Tracing an Algorithm with a Trace TableNew Determining What a Simple Algorithm Does (Purpose)New Why Different Algorithms Can Solve the Same ProblemNew Comparing Algorithms by Time Efficiency (Faster vs Slower)New Linear Search: How It Works (Mechanics)New Linear Search: Tracing Step-by-StepNew Binary Search: Why the Data Must Be SortedNew Binary Search: How It Works (Mechanics)New Binary Search: Tracing Step-by-StepNew Linear vs Binary Search: Advantages and DisadvantagesNew Merge Sort: Splitting a List into HalvesNew Merge Sort: Merging Two Sorted ListsNew Merge Sort: Tracing a Full ExampleNew Bubble Sort: Swapping Adjacent ItemsNew Bubble Sort: Passes, Comparisons and SwapsNew Bubble Sort: Tracing a Full ExampleNew Merge Sort vs Bubble Sort: Advantages and DisadvantagesNew

Integer, Real and Boolean Data TypesNew Character and String Data TypesNew Choosing the Right Data Type for a VariableNew Variables and Assignment (Storing and Updating Values)New Constants and Why They’re UsefulNew Meaningful Identifier Names (Readable Code)New Sequence: Running Statements in OrderNew Selection: IF, ELSEIF, ELSE DecisionsNew Nested Selection (IF Inside IF)New Count-Controlled Iteration (FOR Loops)New Condition-Controlled Iteration (WHILE / REPEAT UNTIL)New Avoiding Infinite Loops (Correct Conditions)New Arithmetic Operators: +, -, *, /, DIV, MODNew Order of Operations in ExpressionsNew Relational Operators: =, ≠, <, >, ≤, ≥New Building Conditions with Relational OperatorsNew Boolean Operators: AND, OR, NOTNew Combining Boolean Conditions (With Brackets)New One-Dimensional Arrays: Indexes and BoundsNew Iterating Through a 1D ArrayNew Two-Dimensional Arrays: Rows, Columns and IndexesNew Iterating Through a 2D Array (Nested Loops)New Records: Fields Inside a Single Data ItemNew Arrays of Records (Lists of Structured Items)New Input from a User (Keyboard / Form Input)New Output to a User (Screen / Console Output)New String Length and String IndexingNew Substrings and String SlicingNew Concatenating StringsNew Converting Between Characters and Character CodesNew Random Number Generation (Range and Use Cases)New Using Randomness in Algorithms (Games / Sampling)New Subroutines: Why We Use Them (Decomposition in Code)New Procedures vs Functions (Return Values)New Passing Parameters into a SubroutineNew Using Return Values from FunctionsNew Local vs Global Variables (Scope Basics)New Data Validation: Presence, Length and Range ChecksNew Data Validation: Format Checks (e.g. Type/Pattern)New Authentication: Usernames, Passwords and AccessNew CAPTCHA: Why It’s Used and What It StopsNew Common Programming Errors: Syntax vs LogicNew Testing Strategies: Normal, Boundary and Erroneous Test DataNew Debugging: Finding and Fixing Errors from Test ResultsNew

Decimal, Binary and Hexadecimal BasesNew Why Computers Use BinaryNew Bit Patterns: Same Bits, Different Meanings (Text/Image/Sound/Number)New Why Hexadecimal Is Useful in ComputingNew Binary Place Value (8-bit Numbers 0–255)New Writing Decimal Numbers (0–255) in BinaryNew Hex Place Value and Hex Digits (0–F)New Writing Decimal Numbers (0–255) in HexNew Converting Binary to DecimalNew Converting Decimal to BinaryNew Converting Binary to Hex (Nibble Grouping)New Converting Hex to Binary (Nibble Expansion)New Converting Decimal to HexNew Converting Hex to DecimalNew Bits and Bytes (b vs B)New Decimal Prefixes: kB, MB, GB, TB (Powers of 10)New Comparing File Sizes Using PrefixesNew Adding Two Binary Numbers (With Carry)New Adding Three Binary Numbers (Column Rules)New Logical Shifts Left and Right (8-bit)New Using Shifts for Multiply/Divide by Powers of 2New What a Character Set IsNew 7-bit ASCII: Using an Encoding TableNew Unicode: Why It Exists and Its Advantages over ASCIINew Converting Characters to Codes (Using a Given Table)New Converting Codes to Characters (Using a Given Table)New Pixels and How a Bitmap Image Is StoredNew Image Resolution and Colour DepthNew Calculating Image File Size (Resolution × Colour Depth)New How Changing Resolution Affects Image Quality and File SizeNew How Changing Colour Depth Affects Image Quality and File SizeNew Sampling Sound: From Analogue to DigitalNew Sampling Rate and Sample Resolution (Bit Depth)New How Sampling Choices Affect Sound QualityNew Calculating Sound File Size (Rate × Resolution × Time)New Why Data Compression Is UsedNew Lossy vs Lossless Compression (What Changes, What Doesn’t)New Run-Length Encoding: Creating Compressed DataNew Run-Length Encoding: Decompressing Back to OriginalNew Huffman Coding: Frequency Tables and IdeaNew Huffman Coding: Building/Using a Huffman TreeNew Huffman Coding: Calculating Bits SavedNew

Hardware vs Software (What Each Means)New How Hardware and Software Work TogetherNew Boolean Values: True/False as 1/0New The NOT Gate: Truth Table and MeaningNew The AND Gate: Truth Table and MeaningNew The OR Gate: Truth Table and MeaningNew The XOR Gate: Truth Table and MeaningNew Logic Gates with Three Inputs (Truth Tables)New Drawing Logic Circuits Using Gate SymbolsNew Reading a Logic Circuit to Produce a Truth TableNew Combining Logic Gates into Larger CircuitsNew Boolean Expressions from Logic CircuitsNew Logic Circuits from Boolean ExpressionsNew System Software vs Application SoftwareNew The Purpose of an Operating SystemNew OS Management: Memory, Processor, Devices and UsersNew Utility Software: What It Is and ExamplesNew Low-Level vs High-Level Programming LanguagesNew Machine Code: What It Is and Why It’s Processor-SpecificNew Assembly Language: What It Is and Why It’s UsedNew Translators: Compiler, Interpreter and AssemblerNew Compiler vs Interpreter (Key Differences)New What Main Memory Does in a Computer SystemNew CPU Components: ALU, Control Unit and ClockNew Registers and Their Role (No Specific Registers Needed)New Buses: What They Are and Why They MatterNew The Fetch-Decode-Execute Cycle (Full Cycle)New What Affects CPU Performance: Clock SpeedNew What Affects CPU Performance: Cores and CacheNew RAM vs ROM (Volatile vs Non-Volatile)New Cache and Registers: Why They ExistNew Main Memory vs Secondary StorageNew Why Secondary Storage Is NeededNew Magnetic Storage: How It Stores DataNew Solid State Storage: How It Stores Data (High Level)New Magnetic vs Solid State: Pros and ConsNew Cloud Storage: What It MeansNew Cloud Storage vs Local Storage: Pros and ConsNew Embedded Systems: What They AreNew Embedded vs Non-Embedded Systems (Examples)New

What a Computer Network IsNew Advantages of Using NetworksNew Disadvantages and Risks of NetworksNew PAN: What It Is (Bluetooth Only)New LAN: What It Is (Size and Ownership)New WAN: What It Is (The Internet as a WAN)New Wired vs Wireless Networks (Key Differences)New Wireless vs Wired: Advantages and DisadvantagesNew Copper vs Fibre Cabling (When Each Is Appropriate)New What a Network Protocol IsNew IP: Addressing and Routing (Purpose)New TCP: Reliable Transmission (Purpose)New HTTP: How Web Pages Are Transferred (Purpose)New HTTPS: What Changes Compared to HTTP (Purpose)New SMTP: Sending Email (Purpose)New IMAP: Retrieving Email (Purpose)New Why Network Security MattersNew Authentication on Networks (Users and Permissions)New Encryption on Networks (Protecting Data in Transit)New Firewalls: What They Do and How Rules WorkNew MAC Address Filtering: Allowing/Blocking DevicesNew Layering Security Methods Together (Defence in Depth)New The TCP/IP 4-Layer Model: Names of the LayersNew Application Layer: What Happens HereNew Transport Layer: What Happens HereNew Internet Layer: What Happens HereNew Link Layer: What Happens HereNew Which Protocols Sit in Which TCP/IP LayerNew

What Cyber Security MeansNew The Main Purposes of Cyber SecurityNew Social Engineering: What It IsNew Blagging (Pretexting): How It WorksNew Phishing: How It Works (Email/SMS)New Shouldering (Shoulder Surfing): How It WorksNew Protecting Against Social Engineering (Practical Behaviours)New Malware: What It Is (Umbrella Term)New Computer Viruses: How They Spread and HarmNew Trojans: Disguised Malware and Its RisksNew Spyware: Monitoring Users and Stealing DataNew Protecting Against Malware (Practical Steps)New Pharming: Redirecting Traffic to Fake WebsitesNew Weak/Default Passwords: Why They’re DangerousNew Misconfigured Access Rights: How They Create RisksNew Removable Media Threats (e.g. Infected USBs)New Unpatched/Outdated Software: Why It’s a ThreatNew Penetration Testing: What It Is Used ForNew Pen Testing: Internal Attack SimulationNew Pen Testing: External Attack SimulationNew Biometrics for Security (Especially Mobile Devices)New Password Systems (Strong Password Practice)New CAPTCHA and Automated Attack PreventionNew Email Confirmations for Identity CheckingNew Automatic Software Updates as ProtectionNew

What a Database IsNew What a Relational Database IsNew Tables, Records and Fields (Core Vocabulary)New Data Types in Databases (Why They Matter)New Primary Keys: Unique IdentifiersNew Foreign Keys: Linking Tables TogetherNew Reducing Redundancy and Inconsistency with Relational DesignNew SELECT: Choosing Which Fields to ShowNew FROM: Choosing Which Table(s) to UseNew WHERE: Filtering Records by a ConditionNew ORDER BY: Sorting Results ASC and DESCNew Writing Queries Using Two Tables (Maximum)New INSERT INTO: Adding a New RecordNew UPDATE: Editing Existing Data Safely with WHERENew DELETE: Deleting Records Safely with WHERENew

What “Ethical Impact” Means in Digital TechnologyNew What “Legal Impact” Means in Digital TechnologyNew What “Environmental Impact” Means in Digital TechnologyNew Privacy: What People Expect and Why It MattersNew Security vs Privacy: The Core Trade-Off (Safety vs Access)New Evaluating a Scenario: Stakeholders, Benefits and RisksNew Cyber Security Impacts: Protection, Surveillance and HarmNew Mobile Technologies: Location Tracking and Personal DataNew Wireless Networking: Convenience vs Eavesdropping RisksNew Cloud Storage: Data Ownership, Access and Jurisdiction IssuesNew Cloud Storage: Reliability, Outages and Dependency RisksNew Hacking (Unauthorised Access): Harm, Motivations and ConsequencesNew Wearable Tech: Health Data, Consent and Data SharingNew Computer-Based Implants: Safety, Consent and Data SecurityNew Autonomous Vehicles: Safety, Liability and Decision-Making EthicsNew Environmental Costs: Energy Use of Devices and Data CentresNew Environmental Costs: E-waste and Product LifecyclesNew Key UK Digital Laws (Overview: Data, Access, Copyright, Info Rights)New

Designing a Program to Meet a BriefNew Writing a Program in a Text-Based High-Level LanguageNew Testing a Program SystematicallyNew Refining a Program Based on Test EvidenceNew Using Programming Tasks to Build Exam-Ready SkillsNew What the Practical Programming Statement Confirms (Opportunity to Practise)New Avoiding Malpractice in Practical Programming EvidenceNew

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Computer Science

Exam Questions

Fundamentals of algorithms (AQA)

Programming (AQA)

Fundamentals of data representation (AQA)

Computer systems (AQA)

Fundamentals of computer networks (AQA)

Cyber security (AQA)

Relational databases and structured query language (SQL) (AQA)

Ethical, legal and environmental impacts of digital technology (AQA)

Programming skills and practical programming statement (AQA)

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