Electronics and Information Technology

Modern life runs on electronics and information technology. Phones, networks, sensors and software now sit inside farming, banking, medicine and government. Exams test this area through short, current-affairs style questions. The questions return to the same core ideas: how computers think, how the internet works, how devices talk to each other, how smart devices sense the world, and how all of this is kept secure. This topic covers each of these in turn.

Artificial Intelligence (AI) is the ability of a machine to perform tasks that normally need human intelligence. Within it sit two nested fields:

• Machine learning (ML): a subset of AI. The machine learns patterns from data instead of following fixed rules.
• Deep learning: a subset of machine learning. It uses layered neural networks, loosely modelled on the brain, to learn from very large amounts of data.

At its present level of development, AI can already do many practical things:

• bring down electricity consumption in industrial units by optimising machines and processes
• detect and diagnose diseases from medical scans and records
• convert text to speech and speech to text

Two claims sit outside this list and trap candidates. Creating genuinely meaningful short stories and songs is treated as beyond AI at its present state of development, so that option is marked incorrect. Transmitting electrical energy wirelessly is not an AI task at all. It is an electrical engineering problem.

Quantum computing is the next frontier. An ordinary computer stores information in bits, each either 0 or 1. A quantum computer uses qubits, which can hold combinations of 0 and 1 at once, so some problems can be solved far faster. Majorana 1, announced in 2025, is a quantum computing chip introduced by Microsoft, not Amazon Web Services. It is built around a new "topological" qubit design intended to make quantum computers more stable.

Exams also pair famous science terms with their fields. Three that have been tested:

• Belle II experiment: particle physics (an accelerator experiment in Japan), not artificial intelligence.
• Blockchain technology: digital records and cryptocurrency.
• CRISPR-Cas9: gene editing in biology, not particle physics.

The web has evolved in stages. Web 1.0 was read-only pages. Web 2.0 added user content and social media, but big platforms control the data. Web 3.0 is the proposed next stage: a decentralised web where users control their own data and digital identities through blockchain, without depending on a central company. A single world standard for Web 3.0 does not exist.

• Blockchain is a digital ledger shared across many computers. Every participant holds a copy, and entries cannot be quietly altered. This makes a central authority unnecessary. Blockchains have uses well beyond cryptocurrency, such as land records and supply chains.
• Cryptocurrencies (like Bitcoin) are digital money kept on blockchains.
• Non-Fungible Tokens (NFTs) are blockchain entries that prove ownership of a unique digital item, such as digital art. "Non-fungible" means one token cannot be swapped for another as equals, unlike money or Bitcoin, where any unit equals any other. NFTs enable the digital representation of physical assets and can be traded.
• The metaverse is an interoperable network of 3D virtual worlds that millions of users can enter at the same time, with property rights over virtual items.

Cloud computing means using computing power and software over the internet instead of owning it. In the Software as a Service (SaaS) model, the provider runs the application and users access it online. SaaS buyers can customise the user interface and can change data settings, and multiple users can share a single instance of the application.

A Virtual Private Network (VPN) is a private, secure communication tunnel created over a public network such as the internet. It lets a remote user reach an organisation's internal network as if connected directly, with the data encrypted in transit.

Wireless systems differ in range, speed and purpose. The tested ones:

• GSM family: the evolution path of mobile telephony standards that includes GSM, GPRS, EDGE and, further along the same path, LTE. CDMA-based standards and Wi-Fi do not belong to it. Nor does DSL (Digital Subscriber Line), a wired broadband technology that carries data over ordinary telephone lines. When asked which term does not belong with the GSM family, the answer is DSL, not LTE.
• LTE (Long-Term Evolution): the 4G mobile data standard, commonly marketed as 4G LTE. On plain LTE, voice calls fall back to the older network. VoLTE (Voice over LTE) carries voice calls as data on the 4G network itself, so calls connect faster and sound clearer. LTE is data capable, and VoLTE adds voice on the same network. Both are mobile network technologies, and VoLTE is not a separate radio technology from LTE.
• Wi-Fi vs Bluetooth: Bluetooth links devices over short ranges (about 10 metres) with low power, for example a phone and an earphone. Wi-Fi covers longer ranges at much higher speeds and connects devices to a network. The frequency bands separate them: Bluetooth works in the 2.4 GHz band, while Wi-Fi can use either the 2.4 GHz or the 5 GHz band. Neither needs a line of sight between devices; both work through walls. Bluetooth and Wi-Fi are different standards, and a device can use both.
• Near Field Communication (NFC): very short range wireless, a few centimetres, used for contactless payments by tapping a card or phone. It works on radio waves and can operate securely with encryption.
• Li-Fi (Light Fidelity): transmits data through light from LED bulbs rather than radio waves. It offers very high speeds but works only within the lit area, since light cannot pass through walls. Li-Fi is a form of Visible Light Communication (VLC). VLC uses visible light between roughly 375 and 780 nanometres and is line-of-sight. Because light stops at walls, VLC is a short-range optical wireless technology; calling it long-range is the standard incorrect statement. VLC can transmit large amounts of data faster than Bluetooth, and it is free of electromagnetic interference, since light does not disturb radio equipment.
• RFID (Radio Frequency Identification): small radio tags read at a short distance, used to track goods, library books and toll passes.
• Radar sends out radio waves and reads their reflections. Its uses now go well beyond tracking aircraft and ships. Weather radar monitors precipitation. Radar-based body scanners and imaging systems help detect narcotic drugs concealed on passengers. Specialised wildlife radar also tracks the migration of animals, especially flocks of birds and bats. All three activities, narcotics detection, precipitation monitoring and animal-migration tracking, are possible with radar.

Spectrum regulators group several low-power everyday technologies as short-range devices. Their signals travel only modest distances and pose little interference risk. The tested trio:

• CCTV cameras: wireless closed-circuit television links operate over short distances.
• RFID devices: tags are read at close range.
• Wireless LAN (Wi-Fi): although it reaches farther than Bluetooth, it still counts as a short-range device.

All three, CCTV, RFID and Wireless LAN, are correctly classified as short-range devices.

The Internet of Things (IoT) is the network of everyday objects fitted with sensors and internet connections so they can sense, report and act without human input. The classic exam scenario describes a morning where the alarm switches on the geyser, the mirror shows the weather, the refrigerator orders groceries and the car reroutes around traffic. The term that best applies to that whole scenario is the Internet of Things.

Smart devices rest on sensors and related technologies:

• An accelerometer detects motion and tilt. It deploys car airbags on collision, parks a falling laptop's hard drive, and rotates a phone's display between portrait and landscape.
• Wearable devices (smart watches, fitness bands) can monitor location, sleep and heart rate. They do not measure drunkenness, which is a trap option.
• Biometric identification can use more than fingerprints: iris scans, retinal scans and voice recognition all work. Signature and photograph are not biometric in the strict sense used by these systems.
• Drones (unmanned aerial vehicles) can spray pesticides on crop fields, inspect the craters of active volcanoes, and even collect breath samples from spouting whales for DNA analysis. All three are possible at the present level of technology.
• 3D printing builds objects layer by layer from a digital design. It already has applications in confectionery, prosthetics and artificial body parts, automobile and aircraft parts, and even small buildings. It also serves the manufacture of bionic cars and the making of components for data processing technologies. When a question lists all five of these applications, the answer is all five.
• Augmented Reality (AR) overlays digital images on the real world seen through a device, so a perceived physical reality is created. Virtual Reality (VR) immerses the user in a fully computer-generated environment, cutting out the real surroundings. AR mixes real and digital. VR replaces the real.

Connected systems attract attacks, so security has its own vocabulary and law.

• Malware is malicious software. WannaCry and Petya are ransomware attacks that locked computers worldwide in 2017 and demanded payment. EternalBlue is the software flaw they exploited. All three relate to cyber attacks and ransomware.
• A digital signature is an electronic method of signing a document. Its job is to ensure that the original content of the document is unchanged. That is the only correct definition for exams. Although Indian law requires it to be issued through a licensed Certifying Authority, a digital signature is not itself an electronic record that identifies the certifying authority issuing it. It is also not a general proof of identity for accessing the internet, and it is not a secret password shared between sender and receiver.
• CERT-In (the Indian Computer Emergency Response Team) is the national agency for responding to cyber incidents. In India it is legally mandatory for service providers, intermediaries, data centres and body corporates to report cyber security incidents to CERT-In.
• Cyber insurance for individuals generally covers three things: the cost of restoring the computer after malware disrupts access to data, the cost of a specialised consultant hired to minimise the loss in a case of cyber extortion, and the cost of defending a claim in a court of law. It does not cover the cost of a new computer when someone wilfully damages the system. Deliberate physical damage is the usual trap option.