FCC General License Test Question

Difficult to give an answer if the question seems wrong......Do you really mean peak-to-peak here?...or should it say 400v and 1000v peak-to-peak respectively?

Both are oscilloscope peak to peak readings.

200V peak to peak equal 100Vmax (Vmax=Vpk-pk/2) 100Vmax=70.7Vrms (Vrms=Vmax*0.707) and the PEP = Vrms^2/Rl, so PEP=70.7^2/50≈100W in the first example. The second example is 625W. Notice that this measurement mostly refers to AM where the amplitude is not constant. the maximum peak power and the average power are different. If you measure the average power by proxy (heat emission) you'll get a much smaller value than this. For FM the ,,PEP'' power is the real power dissipated into the load, because the amplitude is constant and at maximum. I hope this helps. I'd be glad to further disambiguate the subject (as much as I can)

And PEP mostly refers to the measurement of an Amplitude Modulated Signal. Basically for AM PEP≠Pavg, whereas for FM and PM PEP=Pavg

Isn't @Imccoig confusing 'peak' oscilloscope readings with 'peak-to-peak' oscilloscope readings here

The bugger is right fot the shown signal. Sqrt(2) is correct for a sinus only.

The shown top signal is not 200v peak to peak...the shown signal here is 200v peak. (400v peak to peak).

Yes by the way, peak to peak is the sum of both polarities, so the upper example has a Vpk-pk=400V and the lower example 1kV.

@ thebugger, great job! Right answers and peak to peak conversion to voltage in RMS before the wattage formula. Thanks for showing the math.

I did not realize I had voltages too high in simulator. Sorry for causing that confusion!

It's okay I did the math based on your description, not the simulation. I wouldn't have even noticed if 2ctiby hadn't said something about it. Anyway I took the FCC test and my advice is to be careful, some questions are quite misleading.