Question

Find the power reflected in a transmission line, when the reflection coefficient and input power are 0.45 and 18V respectively.

(a) 3.645

(b) 6.453

(c) 4.563

(d) 5.463

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This question is from Reflection and Transmission Coefficients topic in chapter Transmission Lines of Electromagnetic Theory

Answer 1

Correct choice is (a) 3.645

Explanation: The ratio of the reflected to incident amplitudes gives the reflection. Similarly, the ratio of reflected to incident power gives square of the reflection coefficient. Thus Prefl = R^2Pinc. On substituting for R = 0.45 and Pinc = 18, we get Prefl = 0.45^2 x 18 = 3.645 units.