Electric Circuits 8th Edition 86

Electric Circuits 8th Edition 86 - Kirchhoff's laws.To aid...

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62 Simph Rsistive Circuits objective 1-Be abte to recognize resistors conneded in 3.1 For tbe circuit shown, find (a) the vollage o, (b) the power delivered to the circuil by the cufent source, and (c) the power dissipated in the 10 () resistor. Answer: (a) 60Vr (b) 300 w; (c) s7.6w NOTE: Also try Chapter Problems 3.1,3.2,3.5, and 3.6. series and in parattel 7.211 101) (") (b) Figure 3.12 a (a) A votiase-divider circuit and (b) the vottagsdivids circuit with crrent ; indicaied. -Rr 01 =rr(1 : ?rnr + R2, .- R, 02 = u<2: xsRt + R, (3.20) (3.21) 13.22) 3.3 The \foltage-Sivider and eurrent-Sivider eireuits Al timss especially in eleclronic circuils developing more than one voltage level from a single vollage supply is necessary. One way of doing this is by using a voltsge-divid€r
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Unformatted text preview: Kirchhoff's laws.To aid the analysis, we introduce the curent i as shown in Fig. 3.12(b). From Kilchhoff's current la\ Rr and R, carry the same cur-rel1l.Applyilg Kilchhoff's voltage law around the closed loop yields r . - l R r + i R z , R r + R , Now wc can use Ohm's law to calculale ul and ,2: Equations 3.21 and 3.22 show that ,r and o, are fractions of o,- Each ftaction is the ratio of the resistance across which rhe divided voltage is defined to the sum ofthe two resistances. Because this ratio is always lcss than 1.0. the divided voltages or and ?J2 are always iess than the source If you desire a particular valuc of ?)2, and o, is specified, an infinile number ofcombinarions of Rr and R, yicld thc propcr ratio. For example, suppose that !. equals 15 V and 1J2 is to bc 5 V Thon r2/o, = i and, liom...
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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 University of California, Berkeley.

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