RLC circuit impedance problem

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
6 replies · 3K views
chemistrymole
Messages
17
Reaction score
0

Homework Statement

Homework Equations


Impedance formula and couple others.

The Attempt at a Solution

 
Last edited:
Physics news on Phys.org
chemistrymole said:

Homework Statement


A series RLC circuit contains 4.2 ohm resistor, a 42mH inductor and a 22 microfarad capacitor. it is powered by a 120 V (rms) alternating current. what is the total impedance (Z) of the circuit?

I think I need to assume the Hz which is 377 Hz and then convert into 377/2pi which is cyclic Hz I get 60Hz. The problem does not give this. Am I suppose to assume this? Otherwise I cannot use the formula such as XL=wL and so on.

Does anyone see a different route to find Z.
You definitely need to be given the frequency. Both L and C have impedances which are dependent on frequency.

I'm sure you meant to write that 377 radians/second equates to 60 Hz. :wink:

If all of your exercises so far have involved 60 Hz, then I guess you will have to assume that here, but generally the frequency should be part of the specification---you should not assume some value.

The best course would be to work it out using algebra, keeping frequency as "f", and making that expression your answer. Then, as a final step, maybe state an assumption of 60 Hz, and evaluate the expression. That way, you have all bases covered. :smile:
 
Last edited:
Thank yo so much. I think I will use blank Hz since the problem link the professor uses the same. My professor is very laid back he will still mark it correct even if I use any frequency because he will see my work and know I know how to solve it. Thanks again!
 
Last edited:
How can I delete this entire post? I don't want students from my class who are lazy to google and get this easily. Can yo please remove.
 
Is there a way you can edit your response and just delete it also the part you quoted on me. I deleted as much as I could.
 
chemistrymole said:
How can I delete this entire post? I don't want students from my class who are lazy to google and get this easily. Can yo please remove.
You can't delete your post or thread. Neither may you edit or abridge it. Once your post is published it must remain. This is a public forum, and is intended for helping all who wish to read here. If you want private tutorial assistance then don't post your questions here. For private coaching you must look elsewhere.

That's the rules.
 
I understand no problem. Thank you for your help though. I will note this for future.