A perfect (no loss) coaxial cable has 7 dB of reflected power when the input is 5 watts. What is the output of the transmission line?

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Multiple Choice

A perfect (no loss) coaxial cable has 7 dB of reflected power when the input is 5 watts. What is the output of the transmission line?

Power reflected on a transmission line is the portion of the input that bounces back toward the source. A 7 dB reflection means the reflected-to-incident power ratio is 10^(−7/10) ≈ 0.1995. So with an input of 5 watts, the reflected power is 5 × 0.1995 ≈ 1 watt. Since the line is lossless, the remaining power (about 4 watts) travels to the load. The question’s output refers to the reflected portion, which is about 1 watt.

Power reflected on a transmission line is the portion of the input that bounces back toward the source. A 7 dB reflection means the reflected-to-incident power ratio is 10^(−7/10) ≈ 0.1995. So with an input of 5 watts, the reflected power is 5 × 0.1995 ≈ 1 watt. Since the line is lossless, the remaining power (about 4 watts) travels to the load. The question’s output refers to the reflected portion, which is about 1 watt.

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