In the 2-port network shown in the figure the value of Y₁₂ is

Concept:

Y parameters are also known as short circuit parameters.

In Y parameters input and output currents are represented in terms of input and output voltages.

I₁ = Y₁₁.V₁ + Y₁₂.V₂

I₂ = Y₂₁.V₁ + Y₂₂.V₂

Calculation:

To calculate Y₂₁ input port should be short-circuited

\(Y_{21} =\frac{I_1}{V_2}|_{V_1=0}\)

Applying KCL at node V

\(\frac{{{V_a}}}{1} + \frac{{{V_a}}}{1} + \frac{{{V_a} - {V_2}}}{1} = 0\)

V₂ = 3.V_a ----(1)

Also

V­­_a = -I₁ ----(2)

From equation (1) and (2) we get,

\({Y_{21}} = \frac{{{I_1}}}{{{V_2}}}|_{V_1=0} = - \frac{1}{3}\)

Important Points