For the two port network shown in the Fig. the $$Z$$ $$-$$ matrix is given by

Two networks are connected in cascade as shown in the Fig. With the usual notations the equivalent $$A,B,C$$ and $$D$$ constants are obtained. Given that, $$C$$ $$ = 0.025\angle {45^ \circ },$$ the value of $${Z_2}$$ is

The set-up in the figure is used to measure resistance $$R$$. The ammeter and voltmeter resistances are $$0.01$$$$\Omega $$ and $$2000$$$$\Omega $$, respectively. Their readings are $$2A$$ and $$180$$ $$V$$, respectively, giving a measured resistance of $$90$$ $$\Omega $$. The percentage error in the measurement is

A $$1000$$ $$V$$ $$DC$$ supply has two $$1-core$$ cables as its positive and negative leads: their insulation resistances to earth are $$4\,\,M\Omega $$ and $$6\,\,M\Omega $$, respectively, as shown in figure. A voltmeter with resistance $$50\,\,k\Omega $$ is used to measure the insulation of the cable. When connected between the positive core and earth, the voltmeter reads