Basic DC Theory DC CIRCUIT ANALYSISThird, apply Kirchhoff’s voltage law to loops one and two by picking a point in each loop andwriting a loop equation of the voltage drops around the loop; then set the equation equal to zero.Figure 40 Applying Voltage Law to Loop 1Figure 40 shows Loop one.From Point A to Point B, there is an increase in voltage of 8 volts. From Point C to Point D,there is an increase in voltage of 200 (I_{2} - I_{1}). From Point D to Point E, there is a decrease involtage of 10 volts. From Point E to Point A, there is a voltage decrease of 50I_{1}volts. Theresult in equation form is illustrated in equation (2-16).8 + 200 (I_{2} - I_{1}) - 50 I_{1} - 10 = 0 (2-17)Using the same procedure for Loop 2 of Figure 39, the resulting equation is shown in equation(2-18).10 - 200 (I_{2} - I_{1}) + 40 - 100 I_{2} = 0 (2-18)Fourth, solve equations (2-17) and (2-18) simultaneously. First, rearrange and combine like termsin the equation for Loop 1.-50 I_{1} + 200 I_{2} - 200 I_{1} = 10 - 8-250 I_{1} + 200 I_{2} = 2Divide both sides by two.-125 I_{1} + 100 I_{2} = 1Rev. 0 Page 51 ES-02

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