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A telephonic communication service is working at carrier frequency of 10 GHz. Only 10 % of it is utilized for transmission. How many telephonic channels can be transmitted simultaneously if each channel requires a bandwidth of 5 kHz?

1. 2 × 10³
2. 2 × 10⁴
3. 3 × 10⁵
4. 2 × 10⁶

Correct answer: 2 × 10⁴

Solution

Usable bandwidth = 0.10 x 10 GHz = 1x10^9 Hz. Channels = 1x10^9 / (5x10^3) = 2x10^5.

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