Current in Discharing Capacitor

  • Thread starter Thread starter 05holtel
  • Start date Start date
  • Tags Tags
    Capacitor Current
Click For Summary
SUMMARY

The current in a discharging capacitor is expressed as I = (Q0/RC)e^(-t/RC), where Qd = Q0e^(-t/RC) represents the charge over time. The confusion arises from the differentiation of the exponential function, where the correct derivative is derived from the chain rule, yielding I = dQ/dt = (Q0/RC)e^(-t/RC). The discussion clarifies that the absolute value of current may be considered for simplicity, as current direction can be positive or negative.

PREREQUISITES
  • Understanding of capacitor discharge principles
  • Familiarity with calculus, specifically differentiation
  • Knowledge of exponential functions and their derivatives
  • Basic electrical engineering concepts related to current and charge
NEXT STEPS
  • Study the derivation of the exponential decay function in RC circuits
  • Learn about the implications of current direction in electrical circuits
  • Explore advanced topics in circuit analysis, such as Laplace transforms
  • Investigate practical applications of discharging capacitors in electronic devices
USEFUL FOR

Electrical engineering students, educators teaching circuit theory, and professionals working with electronic components and systems.

05holtel
Messages
52
Reaction score
0

Homework Statement



How do you express the current in a discharging capacitor.

I know that I = dQ/dt,

Qd = Q0e^(-t/RC)
I = d/dt (Q0e^(-t/RC))
= (Q/RC)e^(-t/RC)

I am confused because taking the derivative of Q0e^(-t/RC)) I think should be
(-Q/RC)e^(-t/RC) because the derivative of (-t/RC) is (-1/RC)

Which solution is correct
Thanks in advance
 
Physics news on Phys.org
Don't quote me on this but they may just be taking the absolute value for simplicity, since current can be taken as positive in one direction or negative to point in the other direction.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
19
Views
5K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 5 ·
Replies
5
Views
7K
  • · Replies 2 ·
Replies
2
Views
2K