Complex currents and voltages - current in a branch

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
1 reply · 1K views
Rectifier
Gold Member
Messages
313
Reaction score
4
The problem
I want to calculate ## |I_1| ##

RCMQMNp.jpg


The attempt

## V_m = Z_{total}I_1 \\ I_1 = \frac{V_m}{Z_{total}} ##

## Z_{total} = \frac{ \frac{1}{jwC }\cdot (R + jwL) }{\frac{1}{jwC} + R + jwL} \\ \frac{ R + jwL }{1 + jwCR + jwCjwL} \\ \frac{ R + jwL }{1 - w^2LC + jwCR } \\ ##

## I_1 = \frac{V_m}{Z_{total}} = \frac{V_m}{\frac{ R + jwL }{1 - w^2LC + jwCR }} \\ = \frac{V_m(1 - w^2LC + jwCR)}{R + jwL} ##

## I_1 = \frac{V_m(1 - w^2LC + jwCR)}{R + jwL} \\ |I_1| = \frac{|V_m(1 - w^2LC + jwCR)|}{\sqrt{R^2 + (wL)^2}} ##

This does not look right since the answer is ## \frac{R|V_m|}{R^2 + (wL)^2} ##

Please help me.
 
Physics news on Phys.org
The given answer looks very suspicious since it doesn't include the capacitor impedance in any way. Your result looks okay to me.