If a transmission line has a power loss of 6...

Question 1 of 27070zyti8bAvbmdnGxvEJhjR

If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission line fed by a 100 watt transmitter?

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Question 1 of 27070

Q

If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission line fed by a 100 watt transmitter?

🔍 Key Concepts

• Meaning of decibels (dB) as a ratio, not a direct watt value • Effect of negative dB (loss) on power along a transmission line • How to convert 6 dB steps into power ratios (each 3 dB is about a factor of 2)

💭 Think About

• First figure out the total dB loss over 200 feet if the loss is 6 dB per 100 feet • Convert that total dB loss into a power ratio and apply it to the 100 watt transmitter output • Compare your calculated power to the answer choices and see which is closest

✅ Before You Answer

• Be sure the total line loss in dB is correct for 200 feet, not just 100 feet • Confirm whether each 3 dB of loss cuts the power roughly in half, then apply this idea twice if needed • After converting from dB to a ratio, multiply that ratio by 100 watts to find the power at the antenna feed point