# RCL-parallel, I know current's but how to calculate Z?

#### Jeo

Joined Nov 26, 2006
2
Hi!
I got RCL-parallel, I know current I (for Z), Ir, Ic and Il, so how can I calculate the Z from these informations? (I know voltage source value 10V , R 500 ohm ,L 2,5 mH and C 0,7 uF but it was mentioned that calculate Z with only using currents).

Jeo

#### Papabravo

Joined Feb 24, 2006
13,940
Ohm's law my friend
Rich (BB code):
if V = I * Z then

Z = V / I
That's not acting...It's ALGEBRA!
To compute the branch impedances you don't need the inductance or capacitance values.
To compute the reactances you also need to know the frequency.

#### Jeo

Joined Nov 26, 2006
2
I know that E=IZ but if I need to calculate Z only using branch currents (I know frequency)? Any ideas? There is something about "I is equal to Z and Ic equal to Xc".. Meaby I cheat and use ohm's law..

#### Dave

Joined Nov 17, 2003
6,970
Do you know the currents in polar form? (i.e. complex form) then you can use this tutorial to deduce Z for the parallel arrangement.

Dave

#### JoeJester

Joined Apr 26, 2005
4,264
Well, don't keep us in suspense. Tell us the frequency you used and then show your answers and the work.