What is the total inductive reactance of each circuit of Figure 13-33?
What is the total inductive reactance of each circuit of Figure 13-33?
The reactances of the individual inductors are the same in both circuits. From Equation 13-12 : X_{L}= 2 \pi fL,
X_{L1}= 2\pi fL_{1}= 2\pi (200 \ kHz)(2.7 \ mH)= 3.93 \ K\OmegaX_{L2}= 2\pi fL_{2}= 2\pi (200 \ kHz)(4.7 \ mH)= 5.91 \ K\Omega
For the series inductors in Figure 13-33(a), the total reactance is the sum of X_{L1}and X_{L2}, as given in Equation 13-13 : X_{L(tot)}= X_{L1}+ X_{L2}+ X_{L3}+….+ X_{Ln}.
X_{L(tot)}= X_{L1}+ X_{L2}= 3.39 \ k\Omega + 5.91 \ k\Omega =9.30 \ k\OmegaFor the inductors in parallel in Figure 13-33(b), determine the total reactance by Equation 13-14 : X_{L(tot)}= \frac{1}{\frac{1}{X_{L1}}+ \frac{1}{X_{L2}} + \frac{1}{X_{L3}}+ …….+ \frac{1}{X_{Ln}}} or from the produet-over-sum rule using X_{L1}and X_{L2}
X_{L(tot)}= \frac{X_{L1}X_{L2}}{X_{L1}+ X_{L2}} = \frac{(3.39 \ k\Omega)(5.91 \ k\Omega )}{3.39 \ k\Omega + 5.91 \ k\Omega} = 2.15 \ k\OmegaYou can also obtain the total reactance for either series or parallel inductors by first finding the total inductance and then substituting in Equation 13-12 : X_{L}= 2 \pi fL to find the total reactance