Correct Answer - Option 3 : Unity
Concept:
The reflection coefficient gives the percentage of incident voltage reflected from the load.
Mathematically,
Reflection Coefficient\(= \frac{{\left( {{Z_L} - {Z_o}} \right)}}{{({Z_L} + {Z_o})}}\)
Where ZL is the load impedance and Zo is the characteristic impedance.
Application of Concept:
For open-circuit transmission line
ZL = infinite
Reflection Coefficient\( = \frac{{\left( {1 - \frac{{{Z_o}}}{{{Z_L}}}} \right)}}{{\left( {1 + \frac{{{Z_o}}}{{{Z_L}}}} \right)}}\)
As ZL → ∞
Reflection coefficient = 1
