GK Questions

Deque (Double-Ended Queue) allows insertion and deletion at both front and rear ends, combining features of stack (LIFO) and queue (FIFO). Implemented using arrays or linked lists. Used in palindrome checking, sliding window problems, and browser history management. Time complexity: O(1) for end operations.

Digital India was officially launched on July 1, 2015, with vision to transform India into a digitally empowered society and knowledge economy. Built on three pillars: digital infrastructure as utility, governance & services on demand, and digital empowerment of citizens. Encompasses multiple sub-initiatives.

Encryption transforms plaintext into ciphertext using algorithms and keys, ensuring only authorized parties with decryption key can read the data. Protects data at rest (stored) and in transit (transmitted). Hashing is one-way for integrity; encoding (Base64) is not security; compression reduces size.

Reinforcement Learning (RL) trains agents to make sequential decisions by interacting with an environment and receiving rewards/penalties. Used in robotics, game playing (AlphaGo), autonomous vehicles, and resource optimization. Differs from supervised learning (labeled data) and unsupervised learning (pattern discovery).

NFS (National Financial Switch) is NPCI's largest ATM network in India, enabling interoperability so customers can withdraw cash from any bank's ATM using their debit card. Connects over 2.5 lakh ATMs. RuPay is card network, UPI/IMPS are fund transfer systems. NFS handles ATM transaction routing and settlement.

Binary (base-2) system uses only digits 0 and 1, corresponding to off/on states in digital circuits. All computer data and instructions are ultimately represented in binary. Decimal (base-10), hexadecimal (base-16) are used for human readability but converted to binary for processing.

Network Layer (Layer 3) handles logical addressing (IP addresses), routing packets between networks, and path determination. Routers operate at this layer. Data Link (Layer 2) handles MAC addresses and local delivery; Transport (Layer 4) manages end-to-end connections and reliability.

Patch Management is the process of acquiring, testing, and installing code changes (patches) to fix security vulnerabilities, bugs, or improve functionality. Critical for protecting systems from exploits targeting known flaws. Automated tools and scheduled maintenance windows help streamline patch deployment.

INS Vikrant (IAC-1) is India's first indigenously designed and built aircraft carrier, commissioned in 2022. It incorporates Indian-developed systems including navigation, combat management, and communication. Represents a milestone in India's defense self-reliance (Atmanirbhar Bharat) and technological capability.

BharatNet (formerly NOFN) is one of the world's largest rural connectivity projects, aiming to provide minimum 100 Mbps bandwidth to all 2.5 lakh gram panchayats via optical fiber. Enables delivery of e-governance, tele-education, telemedicine, and digital services to rural India.

2G (specifically GPRS/EDGE enhancements) introduced packet-switched data enabling basic mobile internet, email, and MMS. 1G was analog voice only. 3G brought faster data for video calls and web browsing. 4G enabled HD video streaming and app ecosystems. Each generation built upon previous capabilities.

The Fourth Industrial Revolution (Industry 4.0) blends technologies like AI, IoT, robotics, 3D printing, and biotechnology, blurring lines between physical, digital, and biological domains. India's initiatives like SAMARTH Udyog and National Strategy on AI aim to harness this transformation for inclusive growth.

SSD (Solid State Drive) uses flash memory chips with no moving parts, offering faster boot times, file access, and durability compared to HDDs with spinning platters. SSDs are silent, consume less power, and are resistant to physical shock. Prices have decreased, making SSDs standard in modern devices.

UPI uses Virtual Payment Addresses (VPAs) like name@bank, eliminating need to enter account number/IFSC repeatedly. Users can also save beneficiaries, scan QR codes, or use mobile numbers linked to UPI. This simplifies payments and reduces errors compared to traditional NEFT/IMPS transfers.

CSRF (Cross-Site Request Forgery) tricks authenticated users into executing unwanted actions on a web application where they're logged in. Attacker exploits trust between browser and site. Prevention: anti-CSRF tokens, SameSite cookies, checking referrer headers. Distinct from XSS which injects malicious scripts.

NAT (Network Address Translation) allows multiple devices on a private network to share a single public IP address when accessing the internet. Conserves IPv4 addresses and adds a layer of security by hiding internal network structure. Implemented in routers and firewalls.

In Python, # denotes single-line comments. Multi-line comments use triple quotes (''' or """). Other languages: // and /* */ in C/Java/JavaScript, -- in SQL. Comments improve code readability and documentation but are ignored by compilers/interpreters during execution.

Smart contracts are self-executing programs stored on blockchain that automatically enforce agreements when coded conditions are satisfied. Eliminate intermediaries, reduce fraud, and increase transparency. Used in DeFi, supply chain, insurance, and voting. Code vulnerabilities require careful auditing.

NISAR (NASA-ISRO Synthetic Aperture Radar) is a joint Earth-observation satellite using dual-frequency radar to monitor ecosystems, ice masses, vegetation, and natural hazards. Scheduled for launch in 2024, it will provide unprecedented data for climate science and disaster management globally.

SWAYAM (Study Webs of Active-Learning for Young Aspiring Minds) is a MOOC platform offering free online courses from 9th grade to post-graduation by reputed Indian institutions. Credits earned can be transferred to academic records. Part of Digital India's education transformation initiatives.