Unit 1                                                       

1270                              PRACTICE EXAM SOLUTION Prob 1                                     

 

1.      a. (5 points)

 

         Calculate v1.

 

                   

         b. (5 points)

 

         Calculate i1.

 

 

ans:  a)    40 V

         b)     2 A

 

sol'n:  (a)   The 100 V source is directly across 20 kΩ || 30 kΩ in series with 8 kΩ. Thus, the rest of the circuit is irrelevant in the calculation of v1.

 

 

            (b)  The 10 A source current is in series with 40 kΩ || 10 kΩ. Thus, all of the 10 A must flow through the 40 kΩ || 10 kΩ, and the rest of the circuit is irrelevant in the calculation of i₁. We use the current divider formula, and we may ignore the 100 kΩ resistor.