Question

The Z-parameter matrix for the two-port network shown is

$\left[\begin{array}{cc}2j\omega & j\omega \\ j\omega & 3+2j\omega \end{array}\right]$

Where the entries are in ${}^{\prime }{\Omega }^{\prime }$.

Suppose $Z_b\left(j\omega \right)=R_b+j\omega$

The value of $R_b$ (in $\Omega$) equals

• A. 3

Answer 1

The correct option is A 3

For T-network,
$Z_{11}=Z_a+Z_c$
$Z_{22}=Z_b+Z_c$
$Z_{12}=Z_{21}=Z_c$

Given
$\left[Z\right]=\left[\begin{array}{cc}2j\omega & j\omega \\ j\omega & 3+2j\omega \end{array}\right]$
$\therefore Z_{12}=j\omega$
$and,Z_{22}=3+2j\omega =3+j\omega +j\omega$
$Z_b+Z_c=R_b+j\omega +Z_c$
$\therefore R_b=3\Omega$