For short circuited line, the resulting voltage will be

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The correct answer is Option B: Zero. In a transmission line, a short-circuited termination results in a voltage reflection coefficient of -1. Consequently, the total voltage at the shorted terminal must be zero as per the boundary condition of a perfect short circuit.

Step-by-Step Solution & Concepts:
In a transmission line, a short-circuited termination results in a voltage reflection coefficient of -1. Consequently, the total voltage at the shorted terminal must be zero as per the boundary condition of a perfect short circuit.

Working Principle: When a traveling voltage wave $V_i$ reaches a short-circuited end (where the load impedance $Z_L = 0$), the boundary condition requires the total voltage to be $V_i + V_r = 0$. The reflection coefficient $\Gamma$ is defined as $\frac{Z_L - Z_0}{Z_L + Z_0}$. Setting $Z_L = 0$ yields $\Gamma = -1$, causing the reflected wave to be equal in magnitude but opposite in polarity to the incident wave.

Key Formulas: $V_{total} = V_i + V_r = 0$ — Boundary condition for short-circuited termination; $\Gamma = \frac{Z_L - Z_0}{Z_L + Z_0} = -1$ — Reflection coefficient when $Z_L = 0$

Key Points: A short circuit acts as a perfect sink for voltage, forcing the potential difference to zero.; The reflection coefficient at a short-circuited load is always -1.; Current at a short-circuited terminal becomes twice the incident current due to constructive interference.

Applications: Fault analysis in power systems; Time Domain Reflectometry (TDR) diagnostics

Additional Info: Option A is incorrect because infinity is the result of an open-circuit current reflection.. Option D is the result for the current, not the voltage, at a short-circuited termination.

Answer: B is correct — At a short-circuited termination, the voltage must be zero to satisfy the boundary condition of zero potential difference across the short.

Exam Tip: Always remember: Short circuits kill voltage ($V=0$), while open circuits kill current ($I=0$) at the boundary.

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Option A: Infinity

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Option C: Equal to the incident current

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Option D: Twice the incident current

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