**Unit 2**

1270 **PRACTICE
EXAM SOLUTION Prob 3**

**3. **

Calculate the power furnished or absorbed by the 30V voltage source, and state whether it is furnished or absorbed.

**Solution:**

Because there are several current sources, the node-V method is a good choice here. For node v1:

Our constraint equation: . Substitute this into the node v1 equation:

or

or

or

Current i flowing from + to - in 30 V source:

Power = furnished

Power 120 W furnished (or delivered)

**Check:** Calculate all i's and v's and verify Kirchhoff's
laws.

All sums of currents out of nodes = 0 A

All sums of V-drops around loops = 0 V