GK Questions

Access Control Models define policies for subject-object interactions: DAC (owner-controlled), MAC (system-enforced labels), RBAC (role-based permissions), ABAC (attribute-based rules). Critical for enforcing least privilege and compliance in enterprise systems. Implemented via IAM solutions and directory services.

Switch operates at Data Link Layer (Layer 2), using MAC addresses to forward frames to specific ports within a LAN. More efficient than hubs (broadcast to all ports). Managed switches support VLANs, QoS, and security features. Routers operate at Layer 3 using IP addresses.

UPI transactions are instant and irrevocable once completed. Senders must verify recipient details before confirming. For erroneous transactions, users must contact recipient for refund or raise dispute with bank/NPCI. Always double-check VPA/amount before sending money via UPI.

USB (Universal Serial Bus) is the standard port for keyboards, mice, and most peripherals. Replaced legacy PS/2 ports. USB-C offers reversible connector and higher power/data transfer. Wireless keyboards use Bluetooth or RF dongles, but USB remains universal for wired connections.

Drone Logistics uses unmanned aerial vehicles for last-mile delivery, especially in remote/hilly areas with poor road connectivity. India's Drone Rules 2021 facilitate commercial drone operations. Applications: medical supplies, e-commerce, agriculture spraying. Requires airspace management and safety protocols.

COUNT() returns the number of rows that match a specified condition. COUNT(*) counts all rows; COUNT(column) counts non-NULL values. Used with GROUP BY for segmented counts. Other aggregates: SUM (total), AVG (mean), MIN/MAX (extremes). Essential for reporting and analytics queries.

PSLV has launched over 300 foreign satellites for 34+ countries, establishing ISRO as a reliable, cost-effective launch service provider. Notable missions: PSLV-C37 (104 satellites in one launch), PSLV-C44 (Microsat-R). Commercial launches generate revenue and foster international cooperation.

Inherence-based authentication uses biometric traits inherent to the user: fingerprint, iris, face, voice, or behavioral patterns. Part of multi-factor authentication (MFA). Advantages: hard to lose/share; challenges: privacy concerns, spoofing risks, and accessibility for disabled users.

e-NAM (Electronic National Agriculture Market) is an online trading platform connecting APMC mandis across India. Enables transparent price discovery, wider market access, and reduced intermediation for farmers. Integrated with quality assaying, payment settlement, and logistics services for efficient agricultural trade.

VoIP (Voice over Internet Protocol) transmits voice calls as data packets over IP networks (internet, LAN). Examples: WhatsApp calls, Zoom, Skype, corporate PBX. Advantages: lower cost, integration with apps, advanced features. Quality depends on bandwidth, latency, and jitter management.

CMOS (Complementary Metal-Oxide-Semiconductor) memory stores BIOS/UEFI settings (boot order, system time, hardware config) and is powered by a coin-cell battery (CR2032). If battery dies, settings reset to defaults and system clock loses time. Replacing battery restores persistent storage.

Anomaly detection uses: Supervised Learning (trained on labeled attacks), Unsupervised Learning (clustering normal vs abnormal patterns), and Reinforcement Learning (adaptive response to threats). Combined approaches improve detection of zero-day attacks and reduce false positives in SIEM systems.

DHCP (Dynamic Host Configuration Protocol) automatically assigns IP addresses, subnet masks, gateway, and DNS settings to devices joining a network. Eliminates manual configuration errors and simplifies network management. Uses DORA process: Discover, Offer, Request, Acknowledge.

UPI allows linking multiple bank accounts to one Virtual Payment Address (VPA). Users can select default account or choose at transaction time. Simplifies management, enables fund routing flexibility, and maintains single identity across banks. Managed securely via NPCI's central switch.

Public Wi-Fi networks often lack encryption, allowing attackers on same network to intercept unencrypted traffic (HTTP, emails, credentials). VPN creates encrypted tunnel protecting data in transit. Best practice: avoid sensitive transactions on public Wi-Fi, use HTTPS, enable firewall, and connect via VPN.

Caps Lock toggles alphabetic keys to produce uppercase letters without holding Shift. Shift produces uppercase only while pressed. Caps Lock indicator (LED) shows active state. Useful for typing headings or acronyms; accidental activation is a common user frustration.

Optical Fiber Communication transmits data as light pulses through glass/plastic fibers, offering high bandwidth, low attenuation, and immunity to electromagnetic interference. Backbone of modern internet, undersea cables, and BharatNet. Enables high-speed broadband, 5G backhaul, and data center interconnects.

e-KYC (Electronic Know Your Customer) uses Aadhaar authentication to verify identity digitally, reducing paperwork and processing time. Enabled for banking, telecom, pensions, and subsidies. Consent-based and secure, with audit trails. Supreme Court guidelines ensure privacy and purpose limitation.

JOIN combines rows from multiple tables using related columns (usually primary/foreign keys). Types: INNER JOIN (matching rows), LEFT/RIGHT JOIN (all rows from one side), FULL OUTER JOIN (all rows). Essential for normalized database queries retrieving related data across tables.

Virtualization uses hypervisor software to create multiple virtual machines (VMs) on one physical server, each running independent OS. Improves resource utilization, enables testing, disaster recovery, and cloud infrastructure. Types: full virtualization, para-virtualization, containerization (Docker).