# [Electronics] Frequency where capacitor and inductor have same reactance?

Discussion in 'Homework Help' started by djhughman, Mar 20, 2014.

1. ### djhughman Thread Starter New Member

Feb 25, 2014
3
0
How to calculate frequency in AC series circuit to get capacitor (1μF) and inductor (o.1 mH) to have same reactance?

I know formulas for Xc and Xl but can not put it together.

2. ### Papabravo Expert

Feb 24, 2006
10,338
1,850
Write the following equation:

jωL = 1 / jωC

Now solve for ω = 2πf and what do you get?

3. ### djhughman Thread Starter New Member

Feb 25, 2014
3
0
I have no idea how to solve for ω from jωL = 1 / jωC. Can I get a hint?

4. ### djhughman Thread Starter New Member

Feb 25, 2014
3
0
No idea how to solve for ω from jωL = 1 / jωC. Maybe (jω)^2= 1/C/L? Can I get a hint?
Also what is j? formulas I got do not have that.

5. ### LvW Active Member

Jun 13, 2013
674
100
Perhaps it is "better" to equalize the magnitude only (wL=1/wC).
Otherwise, math makes problems.

6. ### alfacliff Well-Known Member

Dec 13, 2013
2,449
428
how about the resonance formula? one over 2pi times the square root of lc? that should be where the reactances are equal.

Last edited: Mar 23, 2014
7. ### Papabravo Expert

Feb 24, 2006
10,338
1,850
The point was to derive that formula be setting the reactances equal and solving for ω.

8. ### Papabravo Expert

Feb 24, 2006
10,338
1,850
The point was to derive that formula be setting the reactances equal and solving for ω. You get the same formula for series resonance and parallel resonance.