Electric Circuits 8th Edition 123

# Electric Circuits 8th Edition 123 - the unknown node...

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4.2 Introduction to the Node Vottage llethod 99 Using the Node-Voltage Method a) Use the node-vollage method of circuit analysis to fhd the branch currents i., ib, and ic in ihe cir cuit shown in Fi9.4.8. b) Find the powcr associated with each source, and state whether the source is delivering or absorb- ing power. SoIution a) We begin by notingthatthe circuit has two essen- tial nodes; thirs we need to write a single node- voltage expression. We select the lower node as the rcference node and define the unknown node voltage as r,1. Figure 4.9 illustrates these deci' sions. Surming the currenls away fiom node I generates tlle node-vohage equation 5o 1) ' |,nn,,$roo (t Figur€ 4.8 .i, The circuitfor Eranrph 4 2 50v 0, 50 ,1 0l - +i]+i s1040 -3:0 figure 4.9 r. The circuit shown in Fig.4 8 with a rcference node and the unknown This is the end of the preview. Sign up to access the rest of the document. Unformatted text preview: the unknown node voliage or. l-./ Tl'< po\re' a*uciatcd t\irh Ih. <U\ \ourccis 15ov = 50ta = -100w (delivedng). The po$er a. .ocialcd uillr Ihe r A .oLfce ic p3A= 3?,r: 3(40) = 120 w (deh'ering). We check these calculations by noiing that the total delivered power is 220 W.The total power absorbed by the three resisrors is 4(5) + 16(10) + 1(40), or 220W, as we calculalcd and as it Solving for ?J1 gives ; : ' ' = ) A '" 10 40 ' 4 0 Obiective 1-Understand and b€ able to use the node-voltag€ method For the circuit sho\ln, use the node-voltage method to lind r,1, r,2, ancl i1. How much power is delivered to the cfcuit by the 15 A source'l l ) c) Repeat (b) for the 5 A source. Answ€r: (a) 60V 10Y 10A; (b) eoo w; (c) s0w. 5r} F L - - I + ) r r o , | u o n * " n } r n , ( l...
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## This note was uploaded on 07/05/2010 for the course EE 100 taught by Professor Boser during the Spring '07 term at Berkeley.

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