Capacitor separated by a dielectric

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SUMMARY

The discussion centers on the calculation of maximum energy stored in a capacitor separated by a dielectric. The correct formula for energy storage is U = 1/2 * C * V^2, where C is the capacitance and V is the voltage. The error arises from attempting to calculate energy by simply multiplying the maximum voltage (16,000 V) by the maximum charge (3.2e-7 C), which does not account for the voltage drop that occurs when charge is drawn from the capacitor. This highlights the importance of using the correct energy formula in capacitor calculations.

PREREQUISITES
  • Understanding of capacitor fundamentals
  • Familiarity with energy storage equations in electrical circuits
  • Knowledge of dielectric materials and their impact on capacitance
  • Basic principles of voltage and charge relationships
NEXT STEPS
  • Study the derivation of the energy formula U = 1/2 * C * V^2
  • Explore the effects of dielectric materials on capacitance values
  • Learn about the relationship between charge, voltage, and energy in capacitors
  • Investigate practical applications of capacitors in electrical circuits
USEFUL FOR

Electrical engineering students, physics learners, and anyone involved in circuit design or analysis will benefit from this discussion.

EngineerHead
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Homework Statement



REFER TO ATTACHED SCREEN SHOT

Homework Equations


The Attempt at a Solution



My discrepancy is with the last question labeled "Exercise" (What is the maximum energy that can be stored in the capacitor?).

Since the max voltage is 16000V = 16000 J/C, why is multiplying the max voltage by the max charge (3.2 e-7 C) incorrect?
 

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The energy contained is U = 1/2*C*V^2
 
EngineerHead said:
why is multiplying the max voltage by the max charge (3.2 e-7 C) incorrect?
Because were you to start drawing off charge, the capacitor voltage would drop, so you don't have available that amount of charge at the max charged voltage.
 

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