Is the Energy Stored in a Capacitor Really QV Instead of QV/2?

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The discussion centers on the energy stored in a capacitor, with participants agreeing that 0.288 millijoules is the correct value for energy stored. However, there is a debate about whether the energy supplied by the voltage source is actually 0.576 millijoules, which may have been incorrectly printed as the model answer. One participant expresses uncertainty about how to validate the claim regarding the energy supplied by the voltage source. The conversation suggests that the confusion may stem from a misunderstanding of the formula used, potentially mistaking QV for QV/2. Overall, the participants are analyzing the calculations related to energy in capacitors and the implications of the answers provided.
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Attached below. I want to check whether my answer is right because the model answer is 0.576 mJ. Thank you.
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0.288 millijoules looks right.
 
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Yes, 0.288mJ looks correct.
But the energy supplied by the voltage source is 0.576mJ, and maybe that's what they printed as the model answer by mistake.
 
cnh1995 said:
Yes, 0.288mJ looks correct.
But the energy supplied by the voltage source is 0.576mJ, and maybe that's what they printed as the model answer by mistake.
cnh1995: I agree that 0.288mJ looks correct. But I have not been able to see how to support your statement that "the energy supplied by the voltage source is 0.576mJ". Assuming you are correct, is it possible to interpret the assigned calculation to mean the energy supplied by the voltage source?
 
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sojsail said:
But I have not been able to see how to support your statement that "the energy supplied by the voltage source is 0.576mJ".
Well, it can be shown mathematically, but I don't think this problem requires that. :smile:
I mentioned it because I thought perhaps the given wrong answer key had something to do with it.
 
Maybe they mistakenly took the energy to be QV instead of QV/2?
 
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