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15. For the transformer of Fig. 21.59, if the resistive load is
replaced by an inductive reactance of 20 �:
a. Determine the total reflected primary impedance.
b. Calculate the primary current.
c. Determine the voltage across Re and Xe, and find the
reflected load.
d. Draw the phasor diagram.
16. Repeat Problem 15 for a capacitive load having a reactance
of 20 �.
SECTION 21.7 Frequency Considerations
17. Discuss in your own words the frequency characteristics
of the transformer. Employ the applicable equivalent
circuit and frequency characteristics appearing in this
chapter.
SECTION 21.8 Series Connection of
Mutually Coupled Coils
18. Determine the total inductance of the series coils of Fig.
21.60.
19. Determine the total inductance of the series coils of Fig.
21.61.
i
L 1 = 2 H
L 1 = 4 H
M 12 = 1 H
FIG. 21.60
Problem 18.
L 2 = 7 H
20. Determine the total inductance of the series coils of Fig.
21.62.
21. Write the mesh equations for the network of Fig. 21.63.
M13 = 0.1 H
M12 = 0.2 H k = 1
L 2 = 1 H L 3 = 4 H
FIG. 21.62
Problem 20.
+
E
–
k = 0.8
i L1 = 200 mH L2 = 600 mH
R 1
I 1
FIG. 21.61
Problem 19.
L 1
M 12
FIG. 21.63
Problem 21.
L 2
PROBLEMS ⏐⏐⏐ 973
I 2
R L