100+ Free IB Computer Science SL Practice Questions

Topic 1: System fundamentals

Systems in organisations - planning a new system, identifying stakeholders, requirements specification, prototyping; types of system change (direct, parallel, pilot, phased); user training methods (self-instruction, formal class, online); data migration issues; testing strategies (alpha vs beta, dry run); user vs technical documentation; system maintenance (corrective, adaptive, perfective); software development lifecycles (waterfall vs iterative vs agile); legal/ethical/social issues - intellectual property, privacy, GDPR; software licences (proprietary, free, open source, freeware, shareware)

Topic 2: Computer organisation

CPU architecture - control unit, arithmetic logic unit (ALU), registers (MAR, MDR, PC, CIR, Accumulator); main memory RAM vs ROM, cache levels L1/L2/L3; fetch-decode-execute cycle; secondary storage - magnetic HDD, optical CD/DVD/Blu-ray, solid-state SSD and flash; binary representation - denary <-> binary <-> hex conversion, two's complement for negatives; character encoding ASCII vs Unicode; bitmap vs vector images, colour depth, file size calculation; sound representation - sampling rate, bit depth, file size; data compression lossy vs lossless (RLE, Huffman); operating system functions; OS types - single-user/multi-user, single-tasking/multi-tasking, real-time, embedded; multitasking and embedded systems in consumer products

Topic 3: Networks

Network types LAN, WAN, MAN, PAN, VPN; topologies - bus, star, ring, mesh; wired vs wireless including Wi-Fi (IEEE 802.11) and Bluetooth; protocols - TCP/IP, HTTP/HTTPS, FTP, SMTP/POP3/IMAP, DNS, DHCP; OSI 7-layer model and its mapping to TCP/IP; IP addressing - IPv4 vs IPv6, basic subnetting, MAC addresses; firewalls, encryption (symmetric vs asymmetric), SSL/TLS, digital certificates; cloud computing IaaS/PaaS/SaaS; client-server vs peer-to-peer architecture; network hardware - NIC, switch, router, hub, modem, gateway, bridge; data security threats - virus, worm, trojan, spyware, ransomware, phishing, DDoS, MITM; cybersecurity countermeasures

Topic 4: Computational thinking, problem-solving, programming

Computational thinking pillars - decomposition, pattern recognition, abstraction, algorithms; pseudocode in IB notation; flowcharts; constructing algorithms using sequence, selection, iteration; programming concepts - variables, constants, data types (integer, real, character, string, boolean), 1D and 2D arrays, parameters, scope (local vs global), control structures (IF/THEN/ELSE/CASE, FOR loops, WHILE loops); sub-programs - procedures vs functions, parameter passing; algorithm design - linear search vs binary search (O(log n), requires sorted), bubble sort, selection sort, insertion sort; tracing algorithms with trace tables; predicting outputs from pseudocode; common errors - syntax, logic, runtime

Paper 2: Object-oriented programming (Java/Python)

Classes, objects, attributes, methods, instantiation; inheritance - parent/superclass and child/subclass, method overriding; polymorphism; encapsulation - getters/setters, private vs public attributes; UML class diagrams; constructors; static vs instance variables and methods; access modifiers public/private/protected; abstract classes vs interfaces (Java) and Python equivalents

Case study and emerging technologies

Pre-released annual case study - reading and interpreting the scenario, identifying stakeholders and technical challenges; AI concepts - supervised vs unsupervised vs reinforcement learning, neural networks, decision trees, expert systems; ethical issues with AI (bias, accountability, transparency); emerging technologies