Resistance inductance series circuit, parallel capacitance It is known that the power factor is 0.555. In order to improve the power law factor to 0.9, the circuit is composed of a 4-ohm inductor and a 6-ohm inductor in series (with a voltage of 10V at both ends and a phase of 0 degrees), and a capacitor is connected in parallel at both ends of the resistance and inductor to calculate the capacitance value

Resistance inductance series circuit, parallel capacitance It is known that the power factor is 0.555. In order to improve the power law factor to 0.9, the circuit is composed of a 4-ohm inductor and a 6-ohm inductor in series (with a voltage of 10V at both ends and a phase of 0 degrees), and a capacitor is connected in parallel at both ends of the resistance and inductor to calculate the capacitance value

This, this

How to calculate the total impedance of inductance and capacitance in parallel? (electricity)

Z(C)=-j/ωC
Z(L)=jωL
Z=Z(C)*Z(L)/(Z(C)+Z(L))
=-j/ωC*jωL/(-j/ωC+jωL)
=jωL*(1/ωC)/(1/ωC-ωL)
=jωL/(1-ω^2*LC)
When ω ^ 2 * LC is greater than 1, Z is capacitive;
When ω ^ 2 * LC is less than 1, Z is perceptual;
When ω ^ 2 * LC equals 1, Z equals infinity

Parallel calculation of capacitance, inductance and resistance
There is a diagram, resistance, inductance and capacitance are in parallel, not in series
The resistance is 12.5 ohm, the inductive reactance is 5 ohm, and the capacitive reactance is 20 ohm
Excuse me: if these three components are all in parallel, how many should they be,
It's not three in series
Resistance / / J inductance / / - J capacitance
The main problem is how to calculate the parallel connection with complex number
Not admittance, but a specific value

Same parallel formula
1/R=1/12.5+1/5j+1/-20j=1/12.5+(-j/5)+j/20=1/12.5-3j/20=(8-15j)/100
R=100/(8-15j)=100(8+15j)/289
Absolute value r = 5.88
Just remember J = - 1
It's calculated the same way

When parallel resonance occurs in LC circuit, the relationship between the current in inductance L or capacitor C and the total current is (let the quality factor be greater than 1)
The sum of a and B is equal to the total current
C the current in the inductor or capacitor is greater than the total current D cannot be determined
22. The purpose of adding automatic frequency control to the receiver is to make the frequency of the receiver: A. stable B. increase C. decrease D. none of the above is correct

Choose a for both questions