Medium Level – GK Questions

Hyperledger Fabric is a permissioned blockchain framework by Linux Foundation, designed for enterprise use: modular architecture, private channels, pluggable consensus, and identity management. Used in supply chain, trade finance, and healthcare. Contrasts with public chains (Bitcoin, Ethereum) which prioritize decentralization over privacy/performance.

Topology optimization uses algorithms to distribute material optimally within design constraints (loads, boundaries), creating lightweight, efficient structures often with organic shapes. Enabled by additive manufacturing which can produce complex geometries impossible with subtractive methods. Critical for aerospace, automotive, and biomedical applications.

ROS supports Python (for rapid prototyping, AI/ML integration) and C++ (for performance-critical components). Provides libraries for perception, planning, control, and simulation. Widely adopted in research and industry. Understanding ROS architecture is valuable for robotics engineering questions in technical exams.

QKD (Quantum Key Distribution) uses quantum properties (no-cloning theorem, measurement disturbance) to detect eavesdropping during key exchange. If intercepted, quantum states change, alerting parties. Provides information-theoretic security, unlike computational security of RSA/ECC. Deployed in limited networks; scaling challenges remain.

DIDs are self-sovereign identifiers stored on blockchain, giving users control over their digital identity without central authorities. Enable portable profiles, verifiable credentials, and privacy-preserving authentication across metaverse platforms. Part of W3C standards. Critical for user sovereignty and interoperability questions.

Tokenization represents ownership of physical/digital assets (real estate, art, commodities) as blockchain tokens, enabling fractional ownership, instant settlement, and global liquidity. Requires legal frameworks and oracle services for real-world data. Pilots in India for land records, supply chain, and financial assets. Important for fintech innovation questions.

SLAM algorithms use sensor data (LIDAR, cameras, IMU) to build a map of an unknown environment while simultaneously tracking the robot's location within it. Critical for autonomous vehicles, drones, and service robots. Combines probabilistic filtering, optimization, and machine learning. Important for robotics navigation questions.

Advanced metal AM processes (SLM, EBM, DMLS) produce fully dense parts with mechanical properties meeting aerospace/medical standards. Post-processing (heat treatment, machining) may be required. Advantages: design freedom, part consolidation, and rapid iteration. Challenges: cost, surface finish, and certification. Important for advanced manufacturing questions.

Actuators (motors, hydraulic/pneumatic cylinders, piezoelectric devices) convert control signals into physical movement. Types: electric (precise, clean), hydraulic (high force), pneumatic (fast, simple). Critical for robot mobility, manipulation, and interaction. Sensors provide feedback; controllers compute actions; processors run algorithms.

VR headsets (Oculus Quest, HTC Vive) provide stereoscopic 3D visuals, head tracking, and hand controllers for immersive interaction. Standalone headsets require no PC; PC-tethered offer higher fidelity. Emerging tech: haptic feedback, eye tracking, and brain-computer interfaces for deeper immersion. Critical for metaverse access questions.

Private/permissioned blockchains restrict participation to authorized entities, offering higher throughput, privacy, and regulatory compliance. Used in supply chain, trade finance, and consortium applications (e.g., Hyperledger, Corda). Contrast with public blockchains (Bitcoin, Ethereum) which are open and decentralized. Important for enterprise blockchain questions.

PLA (Polylactic Acid) is a biodegradable thermoplastic derived from corn starch, widely used in FDM printing for prototypes, educational models, and hobbyist projects. Easy to print, low warping, and affordable. ABS offers higher strength; PETG combines durability and ease; metals/ceramics require specialized printers.

Computer Vision enables robots to interpret visual data: object recognition, depth estimation, navigation, and manipulation. Combines deep learning (CNNs), sensor fusion, and real-time processing. Critical for autonomous vehicles, warehouse robots, and service robots. Key enabler of intelligent automation systems.

NISQ (Noisy Intermediate-Scale Quantum) devices have 50-1000 qubits with limited coherence. Most promising near-term applications: quantum chemistry (drug discovery, materials), optimization (logistics, finance), and machine learning enhancement. Cryptography breaking requires fault-tolerant quantum computers not yet available.

Interoperability enables avatars, items, and currencies to move between platforms using open standards (like OpenXR, blockchain-based NFTs). Critical for user adoption and metaverse value. Current challenges: proprietary ecosystems, technical standards, and governance. Industry consortia (Metaverse Standards Forum) working on solutions.

SLA (Stereolithography) uses a UV laser to selectively cure photopolymer resin layer by layer, producing high-resolution parts with smooth surfaces. Used for prototypes, dental models, and jewelry. Post-curing and support removal required. One of the earliest additive manufacturing technologies, foundational for resin-based printing.

Reinforcement Learning trains agents to maximize cumulative reward through interactions with an environment. Used in robotics for manipulation, locomotion, and autonomous navigation. Differs from supervised learning (labeled data) and unsupervised learning (pattern discovery). Critical for autonomous systems and AI applications.

Motion capture (using sensors, cameras, or wearables) records human movement and maps it to digital avatars for realistic animation in metaverse platforms. Combined with facial capture and AI for expressive interactions. Critical for immersive social experiences, virtual events, and training simulations. Important for emerging tech questions.

Proof of Work (PoW) requires miners to expend computational power to solve hash puzzles, securing the network and preventing double-spending. Energy-intensive; alternatives include Proof of Stake (PoW's successor in Ethereum), Proof of Authority, and Byzantine Fault Tolerance variants. Critical for understanding blockchain security and sustainability.

Aerospace uses 3D printing (especially metal AM) for lightweight, topology-optimized components like fuel nozzles, brackets, and engine parts. Reduces weight (improving fuel efficiency), consolidates assemblies, and enables rapid prototyping. Also used in healthcare (custom implants), automotive, and defense. Critical for advanced manufacturing questions.