UPSC Prelims 2022 · GS Paper I
Question 36: Science and Technology
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 ?
AnswerUPSC’s answer is (d).
Short-range devices are low-power radio systems that cover only small distances and need little or no licensing. RFID tags and readers, wireless local area networks such as Wi-Fi, and wireless closed-circuit television links all operate over short ranges, so UPSC counts all three as short-range technologies.
- 1. CCTV links operate over short distances.
- 2. RFID reads over short distances at low power.
- 3. WLAN covers a building or campus.
How you could have got this
- If you were sure statement 1 is correct, (b) goes: it leaves 1 out.
What you needed to know: CCTV links operate over short distances.
- Then, if you were sure statement 2 is correct, (c) goes: it leaves 2 out.
What you needed to know: RFID reads over short distances at low power.
- Then, if you were sure statement 3 is correct, (a) goes: it leaves 3 out.
What you needed to know: WLAN covers a building or campus.
Only (d) is left. This one needs every statement.
Which options go is worked out from UPSC’s key and the options, not by a model.
Why each option is right or wrong
- (a) Wrong. WLAN is also short-range.
- (b) Wrong. CCTV is also counted as short-range.
- (c) Wrong. RFID is also short-range.
- (d) Correct. All three are short-range technologies.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2022, General Studies Paper I, Series A. The paper on upsc.gov.in.