Question

Find the load impedance in a quarter line transformer with characteristic impedance of 75 ohm and input impedance of 200 ohm.

(a) 28.125

(b) 12.285

(c) 52.185

(d) 85.128

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This intriguing question comes from Transmission Line Equations topic in division Transmission Lines of Electromagnetic Theory

Answer 1

The correct option is (a) 28.125

The explanation is: For a quarter line wave, the characteristic impedance is the geometric mean of input and load impedances. Thus Zo^2 = Zin ZL. On substituting for Zo = 75 and Zin = 200,  we get ZL = Zo^2/Zin = 75^2/200 = 28.125 ohm.