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SciTech0162 – Near Field Communication (NFC): The Centimetre-Range Technology

Tap your phone to pay and it works instantly. That speed comes from a range so short it’s measured in centimetres, not metres.

NFC tags shown next to a 1 euro cent coin for scale. Photo by Holgerjakobs, via Wikimedia Commons. Licensed CC BY-SA 4.0.

📑 Contents

🏛️ Must Know

What’s True and False About NFC

Uses Electromagnetic Radio Fields NFC genuinely is a contactless communication technology that uses electromagnetic radio fields.
Not a Metre-Range Technology NFC is not designed for devices a metre apart. Its real range is only a few centimetres.
Can Use Encryption NFC genuinely can use encryption when sending sensitive information, such as payment data.

📘 Good to Know

Why NFC’s Short Range Is Actually a Feature

Real Range Is About 4 cm NFC typically works only within about 4 centimetres, unlike Bluetooth or WiFi’s much longer range.
Short Range Improves Security This tight range makes accidental or unauthorised connections much harder, which is part of why it suits payments.
Powers Tap-to-Pay Systems NFC is the technology behind contactless card payments and mobile wallet tap-to-pay systems.

📝 Previous Year Questions

UPSC CSP 2015 — Which NFC Facts Are Correct

UPSC 2015 NFC’s use of electromagnetic radio fields and its encryption capability are correct. The claim that devices can be a metre apart is false; the real range is centimetres. See UPSC CSP 2015 GS Paper I, Q32. View this question.

🌟 Great to Know

Where NFC Shows Up Beyond Payments

Transit and Access Cards NFC also powers metro cards, hotel room keys, and office access badges in many cities.
A Passive and Active Mode NFC tags can work passively, needing no battery, while devices like phones read and write data actively.
Connects to Other PYQ Facts This same short-range-versus-long-range distinction also comes up in UPSC questions comparing WiFi and Bluetooth technologies.