A transmission line has following characteristics :
1. \(Z_L = \dfrac{V_f + V_r}{I_f + I_r}\)
2. \(Z_L = \dfrac{V_f - V_r}{I_f - I_r}\)
3. \(\gamma\) (propagation constant) = \(\sqrt{(R + j\omega L)(G + j\omega C)}\)
4. \(\gamma\) propagation constant) = \(\sqrt{\dfrac{R + j\omega L}{G + j\omega C}}\)
Which of the following is correct option ?
UGC NET - 2013,
Answer: C
Statements 1 and 3 are correct, the third option. The load impedance is the ratio of the total voltage to the total current on the line, as in statement 1, and the propagation constant is \(\gamma = \sqrt{(R + j\omega L)(G + j\omega C)}\), as in statement 3.
Statement 4 is wrong because the expression under the root is the ratio, \((R + j\omega L)/(G + j\omega C)\), and this is the form of the square of the characteristic impedance, not of the propagation constant. Statement 2 is not accepted by the key. So the options with 2 or 4 are wrong.
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