GK Questions

Answer: Subscriber Identity Module

SIM (Subscriber Identity Module) is a small chip that stores subscriber information, network authentication keys, contacts, and SMS. It identifies and authenticates users on cellular networks. eSIM is an embedded digital SIM that can be programmed remotely without physical card replacement.

Answer: Phishing

Phishing is a social engineering attack where attackers impersonate legitimate entities via email/SMS to trick victims into revealing credentials or installing malware. Unlike technical exploits (buffer overflow, SQL injection), social engineering manipulates human psychology. Training and awareness are key defenses.

Answer: SSH

SSH (Secure Shell) provides encrypted remote login and command execution over insecure networks. Replaces insecure Telnet which transmits data in plaintext. SSH uses public-key cryptography for authentication and supports port forwarding, file transfer (SFTP), and tunneling. Default port: 22.

Answer: NavIC

NavIC (Navigation with Indian Constellation) is India's independent regional satellite navigation system with 7 satellites. Provides positioning accuracy better than 20m over India and 1500 km surrounding area. Used in transportation, disaster management, and mobile devices. GLONASS (Russia), Galileo (EU), BeiDou (China) are other global systems.

Answer: PMGDISHA

PMGDISHA (Pradhan Mantri Gramin Digital Saksharta Abhiyan) aims to make 6 crore rural adults digitally literate by training them to operate computers, access internet, use digital payments, and avail e-governance services. Implemented through Common Service Centres (CSCs) across villages.

Answer: Smart Contracts

DeFi protocols use smart contracts to automate financial services: lending (Aave), trading (Uniswap), derivatives, and yield farming. Operate on public blockchains (Ethereum, Solana) with transparent, permissionless access. Risks include smart contract bugs, volatility, and regulatory uncertainty. Critical for fintech innovation questions.

Answer: LIDAR

LIDAR (Light Detection and Ranging) uses laser pulses to create high-resolution 3D maps of surroundings, enabling object detection, classification, and distance measurement. Combined with cameras, radar, and GPS for robust perception. Critical for self-driving cars, drones, and mobile robots. Important for autonomous systems questions.

Answer: NFT Royalties

NFT smart contracts can embed royalty clauses (e.g., 5-10%) that automatically pay creators on each resale in secondary markets. Enables sustainable creator economies in metaverse platforms. Implemented on Ethereum, Polygon, and other chains. Critical for digital ownership and creator monetization questions.

Answer: Heat Treatment

Heat treatment (annealing, stress relieving) reduces residual stresses from rapid melting/solidification in metal AM, improving dimensional stability and mechanical properties. Other post-processing: support removal, machining, surface finishing. Critical for qualifying AM parts for aerospace/medical applications. Important for manufacturing process questions.

Answer: Grover's Algorithm

Grover's Algorithm searches an unsorted database of N items in O(√N) queries vs O(N) classically. Applications: optimization, cryptography, and machine learning. Less dramatic than Shor's exponential speedup but broadly applicable. Requires coherent quantum operations; noise limits practical advantage on NISQ devices.

Answer: Hyperledger Fabric

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.

Answer: Python/C++

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.

Answer: DID (Decentralized Identifiers)

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.

Answer: PolyJet

PolyJet jets photopolymer materials and cures with UV light, enabling multi-material, multi-color printing in a single job with fine detail and smooth surfaces. Used for realistic prototypes, medical models, and consumer product design. More expensive than FDM/SLS but offers superior aesthetics and material combinations.

Answer: Actuator

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.

Answer: VR Headset

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.

Answer: PLA

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.

Answer: Quantum chemistry simulation

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.

Answer: Reinforcement Learning

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.

Answer: Motion Capture

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.