Finding current across capacitor

  • Thread starter Thread starter kayak4life87
  • Start date Start date
  • Tags Tags
    Capacitor Current
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
2 replies · 8K views
kayak4life87
Messages
6
Reaction score
0

Homework Statement


An ac generator with a frequency of 30.0Hz and an rms voltage of 12.0V is connected to a 45.5uF capacitor. a) what is the maximum current in this circuit? b) what is the current in the circuit when the voltage across the capacitor is 5.25V and increasing? c) what is the current in the circuit when the voltage across the capacitor is 5.25V and decreasing?


Homework Equations


Irms=Vrms/Xc Xc=1/2pi(frequency)(capacitor) Io=Irms X square root of 2


The Attempt at a Solution



a) I first solved for Xc and got 116.6Ohms and Irms=12V/116.6Ohms=0.102A
Io=0.102X square root of 2=0.146A
I think i have this part right, but check it for me. thanks.

b) V=5.25V my attempt was to just divide by my Xc, but that does not come out right. the answer is the book is 138mA.

c) -138mA

thanks for the help
 
Physics news on Phys.org
Part a) is good. I think you did parts b and c right too, is your book known to have errors?
 
very very rarely will it have a wrong answer...