Problem 3.5 a.) In the circuits shown in Fig. P3.3 (a)-(d), find the equivalent resistance seen by the source. b.) For each circuit find the power supplied by the source. 45 0 200 25 0 300 60 1 180 50 600 son 150on s0 mAO 40n 75 a"120 30 V 10n 200 2010 300 (a) (b) 300 750 0 100 0 150 250 n 20 V 50 mA 5000 750n 5000 2 k I k 1.2 kn 25 k 2500 300 0 (c) (d)

3.19 For the circuit arrangement shown in Fig.3.66 and for a pure resistive load, sketch a set of waveforms for thyristor triggering a = 90° showing b.b bathe supply current,load current and thyristors voltage. (5) 02-Derive an expression for the average value of the load current Ide and calculate its values for α = 0°, 60°, and 120° if the the supply voltage is ideal sinusoid with Vm 400 V, 50 Hz and the load resisror R =10 2. How is the average load current affected if diode D₂ fails to open circuit? = viqque 1812 is of betosmos a sitiost ballowing av signs grimit & is no-bom ai fi f Fig.3.66. DI Idc D3 R Vac Load Used of getto viqqua Vm sin cot Som box H 2.81 to sonstoubni ne to 21D4D2 60102 92lq-dsH 02 V 004 & mont be 2 5gbrid 10091 92-991bovew-llut bollonnos vilut SS.C [Ans: 12.7 A, 9.5 A, 3.17 A .When diode D₂ failed to open circuit, the circuit will act as a half-wave rectifier]

In the circuit shown in Figure P3.70, VS models thevoltage produced by the generator in a power plant,and RS models the losses in the generator, distributionwire, and transformers. The three resistances model thevarious loads connected to the system by a customer.How much does the voltage across the total loadchange when the customer connects the third load R3in parallel with the other two loads?VS = 110 V RS = 19 mΩR1 = R2 = 930 mΩ R3 = 100 mΩ

3.40 Find Vi and V in the circuit shown in Figure P340. FIGURE P3.40 2 kn R2 V2 4 kn 2000 i 5 V 3 kn 2.5 k 45