Two series coils, each with an L of 250 \mu H, have a total inductance of 550\mu H connected series-aiding and 450 \mu H series-opposing. (a) How much is the mutual inductance L_M between the two coils? (b) How much is the coupling coefficient k?
Two series coils, each with an L of 250 \mu H, have a total inductance of 550\mu H connected series-aiding and 450 \mu H series-opposing. (a) How much is the mutual inductance L_M between the two coils? (b) How much is the coupling coefficient k?
a. L_M=\frac{L_{T_a}-L_{T_o}}{4}
=\frac{550-450}{4}=\frac{100}{4}= 25 \mu H
b. L_M=k\sqrt{L_1L_2}, or
k=\frac{L_M}{\sqrt{L_1L_2}}=\frac{25}{\sqrt{250\times 250}}
=\frac{25}{250}=\frac{1}{10}
=0.1