Capacitor Peak Current and Voltage in an AC Circuit

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
2 replies · 5K views
ReidMerrill
Messages
65
Reaction score
2

Homework Statement


A capacitor has a peak current of 240 μA when the peak voltage at 250 kHz is 2.7 V .
Part A
What is the capacitance?

Part B
If the peak voltage is held constant, what is the peak current at 500 kHz

Homework Equations


Xc=1/wC
Vc=IcXc

The Attempt at a Solution


I rearranged equation 2 to solve for Xc = 2.7V/0.000240A = 11250
I then rearranged equation to to solve for C =1/wXc = 3.56x10-4

This is not correct. Why is this not correct and what is the proper way to go about solving it?
Thank you.

Correction: I re-did the second calculation and got 3.56x10-10F by properly converting kHz to Hz but it's still wrong.
 
Last edited:
on Phys.org
Hi ReidMerrill.
aerobanner.gif


Did you convert kHz to radians/sec?
 
  • Like
Likes   Reactions: ReidMerrill
NascentOxygen said:
Hi ReidMerrill.
aerobanner.gif


Did you convert kHz to radians/sec?
Oh you know what I did not. I wasn't aware I needed to. My professor did not explain this well at all.
I would just divide the frequency by 2pi, correct?EDIT: That worked. Thank you!
 
  • Like
Likes   Reactions: NascentOxygen