Electromagnetic Induction in AC circuits

[Cal66]

A 9.7 Ω resistor, a 10.8 µF capacitor, and a 27.9 mH inductor are connected in series with a 120 V (rms) source with variable frequency.
(a) At what frequency will the current be maximum?

Hz



(b) Find the maximum rms current.

A



(c) Suppose you now replace the 10.8 µF capacitor by a 22.0 µF capacitor. What is the new value of the rms current?

A





a ) frequency f = 1 / 2π √ L C
= 1/ 2π √27.9 mH * 10.8μF
= _____ Hz cannot get right frequency
b ) Maximum rms current Irms = Vrms / XC
XC = 1/ 2π f C
= 1/ 2π * f Hz * 10.8μF
= _____ Ω
Irms = 120 V / XC Ω
= ____
c ) Maximum rms current Irms = Vrms / XC
XC = 1/ 2π f C
= 1/ 2π * f Hz * 22.0μF
= ___ Ω
Irms = 120 V / XC Ω

 

[scottdave]

What value frequency did you calculate? What did they provide as the correct answer?

Why do you divide by X_c to get the current?

 

[Steve4Physics]

What value frequency did you calculate? What did they provide as the correct answer?

Why do you divide by X_c to get the current?

Note that Post #1 is dated 1 April 2010!

 

[scottdave]

Note that Post #1 is dated 1 April 2010!

Ha! These Unanswered Questions just show up... and I'm so into trying to help - I forget to look at the date.