Cordless telephones typically operate within what approximate range?
Electronics and Communication Engineering
Communication Systems
Difficulty: Easy
Choose an option
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A1000 m
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B500 m
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C100 m
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D10 m
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E5 km
Answer
Correct Answer: 100 m
Explanation
Introduction / Context:Cordless telephones are designed for short-range indoor and household communication. Their range is limited by power, frequency, and regulatory restrictions.
Given Data / Assumptions:
- Frequency band: typically 900 MHz, 1.9 GHz, or 2.4 GHz ISM bands.
- Power levels: low, consumer device limits.
Concept / Approach:In practical usage, cordless telephones cover around 30–100 meters indoors, extended slightly outdoors depending on environment.
Step-by-Step Solution:
Indoor walls reduce signal range significantly.Standard specification: ~100 meters in open areas.Therefore, 100 m is the most appropriate option.Verification / Alternative check:Manufacturer datasheets for DECT cordless phones confirm 50–100 m indoor range.
Why Other Options Are Wrong:
1000 m / 500 m: unrealistic for consumer cordless phones.10 m: too small; corresponds more to Bluetooth.Common Pitfalls:
Confusing cordless phones with mobile phones (cellular).Final Answer:
100 m