Easy Discrete in TBR (double checking answer)

[member232]

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Hey guys, this question is a discrete from a TBR CBT. The answer key in the back skipped this question, and its a pretty easy question, so I just wanted to double check what you guys thought the answer was, thanks!

Why are radio and microwave bands chosen for communication signals?

A. Radio and microwave signals have the greatest energy in the EM spectrum, so they provide the clearest signal.
B. Radio and microwave signals have the least energy in the EM spectrum, so they are the least expensive to propagate.
C. Radio and microwave signals have the shortest wavelength in the EM spectrum, so they are subject to minimal interference.
D. Radio and microwave signals have the lowest frequency in the EM spectrum, so any interference to which they are subjected is only constructive interference.

My answer: B

 

[milski]

Looks right, especially considering that all the other answers are wrong.

 

[Singhp03]

Looks right, especially considering that all the other answers are wrong.

👍

i looked at D, but thought why would low frequency have to do anything with a particular interference? suspicious

 

[milski]

👍

i looked at D, but thought why would low frequency have to do anything with a particular interference? suspicious

Correct, destructive or constructive depends only on the phase difference between the two sources - you can get either for any frequency with appropriate situated sources.