GATE EC 2019 Set 1 Q4 — Circuit Analysis

Consider the two-port resistive network shown in the figure. When an excitation of $5\: V$ is applied across Port $1$, and Port $2$ is shorted, the current through the short circuit at Port $2$ is measured to be $1\: A$ (see (a) in the figure).

Now, if an excitation of $5\: V$ is applied across Port $2$, and Port $1$ is shorted (see (b) in the figure), what is the current through the short circuit at Port $1?$