kirchhoff's law problem with solution.

UES_1) .Figure shows parts of a circuit. Calculate the power dissipated in 3ohm resistance. What is the potential difference   V(C) –  V(B)?

SOL :-

Applying kichhoff’s law junction law at E current in wire DE is 8A from D to E. Now further applying junction law at D. The current in 3ohm resistance will be 3  A to D.

Now the circuit is simplified.

Power dissipated in 3ohm resistance = i*i*R = 3*3*3

                                                                         =27 watt.

V(C) – V(B) : V(C) – 5*1 + 12 – 8*2 – 3 – 4*2= V(B)

                        V(C) – V(B) = 5 – 12 + 16 + 3 + 8

                                             = 20 volt.

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