HW 4
1) The coupling coefficient of K’ of a linear transformer is adjusted so that
Zab is purely resistive when w= 25 K rad/s. What is Zab ? The first resistor
is
a
3.2 mH
12.8 mH
b
10ohm and the second resistor is 40ohm
250 nF
2) The voltage source operates at the frequency of 50 K rad/s. The coupling
coefficient K’ of the linear transformer is adjusted until the I1 is maximum.
What is the value of K’ ?
20 Ω
Vg
100 Ω
75 Ω
300 Ω
Ω
➔ I1
5 mH
20 mH
K’
40 nF
When |Zin| is is minimum , I1 is maximum. Thus,
= 0.5657
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