- #1
Is the Energy Stored in a Capacitor Really QV Instead of QV/2?
- Thread starter Clara Chung
- Start date
-
- Tags
- Capacitor
Click For Summary
SUMMARY
The energy stored in a capacitor is accurately calculated as 0.288 millijoules (mJ), while the energy supplied by the voltage source is 0.576 mJ. This discrepancy suggests that the model answer may have incorrectly represented the energy as QV instead of the correct formula QV/2. The discussion highlights the importance of understanding the distinction between the energy stored in the capacitor and the energy supplied by the source, emphasizing the need for clarity in problem statements and answer keys.
PREREQUISITES- Understanding of capacitor energy storage principles
- Familiarity with the formula for energy in capacitors (E = 1/2 QV)
- Basic knowledge of electrical circuits and voltage sources
- Mathematical skills for energy calculations
- Research the derivation of the energy formula for capacitors (E = 1/2 QV)
- Explore the implications of energy conservation in electrical circuits
- Study common misconceptions in capacitor energy calculations
- Learn about the role of voltage sources in energy transfer
Electrical engineering students, educators teaching circuit theory, and professionals involved in electronics design and analysis will benefit from this discussion.
- #2
Asymptotic
- 781
- 529
0.288 millijoules looks right.
- #3
cnh1995
Homework Helper
Gold Member
- 3,487
- 1,163
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.
But the energy supplied by the voltage source is 0.576mJ, and maybe that's what they printed as the model answer by mistake.
- #4
sojsail
- 50
- 9
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?cnh1995 said:
Last edited:
- #5
cnh1995
Homework Helper
Gold Member
- 3,487
- 1,163
Well, it can be shown mathematically, but I don't think this problem requires that.sojsail said:
I mentioned it because I thought perhaps the given wrong answer key had something to do with it.
- #6
- 23,711
- 5,928
Maybe they mistakenly took the energy to be QV instead of QV/2?
Similar threads
- · Replies 9 ·
- · Replies 6 ·
- · Replies 15 ·
- · Replies 19 ·
- · Replies 15 ·
- · Replies 6 ·
- · Replies 5 ·
- · Replies 3 ·