Help with General class question

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Sparkletron

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Can someone help me understand why the answer I selected is not correct...?



First I determined the current using Ohm's law:

E = IR
I = E / R
I = 400VDC / 800R = 0.5A

Then the power:

P = IE
P = 0.5A x 400VDC = 200W
 
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LtDoc

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Nope, I can't explain why your answer was wrong. Using (I^2)R yields 200 watts, like the W=IE equation. What are they asking for if not the answer to one of those formula?
Is this a multi-part question?
- 'Doc
 

Sparkletron

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According to the practice test at QRZ, the correct answer is: 32000W. I have a feeling it's just a mistake with their testing application. The exact question is: G5B03.
 

WA3RDF

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Your answer is correct. I just tried it on QRZ and it showed the right answer. Maybe it was a glitch in the program.
 

Sparkletron

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Thanks for responding. Good thing this was an answer I was confident in. With some of these questions, I'll accept anything they tell me ;-)
 

kc4jgc

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Good thinking!

Since we're allowed up to 1500 watts pep on most bands, it wouldn't seem logical that the correct answer would be a power level we would not legally be able to operate. I would have eliminated that one before doing any math.
 

GrumpyAeroGuy

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When I ran the practice questions on the TECH class using the Technician License Maunal published by ARRL, I also found a few questions where I thought there was a bug, either in the Software, OR in in the actual database regarding the "correct" answer. I can't remember which ones they were now, but one did involve a Resistance and/or power calc, That I remember. Also, there was a question where I think it flagged the incorrect answer as correct on a decibel gain question, or something like that...

Not too many ways to screw up V=IR and P=VI.

My money is on a glitch. ... (??)
 
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