Two passive two-port networks are connected in cascade as shown in figure. A voltage source is connected at port 1. $$\begin{array}{l}Given:\\V_1=A_1V_2+B_1I_2\\I_1=C_1V_2+D_1I_2\\V_2=A_2V_3+B_2I_3\\I_2=C_2V_3+D_2I_3\end{array}$$

$$A_1,\;B_1,\;C_1,\;D_1,\;A_2,\;B_2,\;C_2,\;and\;D_2$$ are the generalized circuit constants. If the Thevenin equivalent circuit at port 3 consists of a voltage source V_T and impedance Z_T connected in series, then

The equivalent resistance between the terminals A and B is ______ Ω.

The following measurements are obtained on a single phase load: $$V = 220 V$$ $$ \pm $$$$1$$%. $${\rm I}$$$$= 5.0$$ $$A$$ $$ \pm \,1$$% and $$W=555$$ $$W$$ $$ \pm \,2$$%. If the power factor is calculated using these measurements, the worst case error in the calculated power factor in percent is _________. (Give answer up to one decimal place.)

The slope and level detector circuit in a CRO has a delay of 100 ns. The start-stop sweep generator has a response time of 50 ns. In order to display correctly, a delay line of