🧷 Authentic Classroom Explanation by IAS Monk

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📌 The Question

Consider the following communication technologies:

1. Closed-circuit Television
2. Radio Frequency Identification
3. Wireless Local Area Network

Which of the above are considered Short-Range devices/technologies?

(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

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✅ Answer

(d)

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🧑‍🏫 Classroom Explanation

Short Range Devices (SRDs) are radio-based devices that operate over short distances with low transmission power, thereby posing minimal interference risk to other radio services.

Let us examine each option:

• 1. Closed-circuit Television (CCTV)
  CCTV systems, especially wireless CCTV, use short-range radio communication for video transmission within confined premises. ✔️
• 2. Radio Frequency Identification (RFID)
  RFID tags and readers typically operate over very short distances ranging from a few centimetres to a few metres, depending on frequency band. ✔️
• 3. Wireless Local Area Network (WLAN)
  WLAN technologies (e.g., Wi-Fi) are explicitly classified as short-range communication systems used within homes, offices, and campuses. ✔️

All three technologies clearly fall under Short-Range Devices.

Hence, option (d) is correct.

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🔍 Curiosity Raiser

Why do short-range technologies intentionally limit their power instead of increasing range for better coverage?

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📚 Enrichment Notes

• Common examples of SRDs:
  • Bluetooth
  • Wi-Fi (WLAN)
  • RFID
  • NFC
  • Remote controls
• Key characteristics:
  • Low transmission power
  • Limited operational range
  • Minimal spectrum interference
• UPSC relevance:
  • IoT ecosystems
  • Smart infrastructure
  • Spectrum management & regulation

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🪔 IAS Monk Whisper

“In communication, power is not dominance; precision is.”