# Category Archives: Basic Concepts

Solved problems in basic concepts of electrical circuits such as Ohm’s Law, power calculation, voltage and current sources

# Problem 1-15: Power of Independent Sources

Determine the power of each source.
a)

b)

Solution
a) The current source keeps the current of the loop $2A$ and the voltage source keeps the voltage across the current source $3v$ as shown below.

# Problem 1-14: Current of A Voltage Source

Find the current passing through the voltage source:
a)

b)

Solution
a) The voltage source is in series with the current source. Since by definition a current source keeps the current passing through itself constant and the voltage source is in series with the current source, it should have the same current $10 A$.

# Problem 1-13: Voltage of A Current Source

Find voltages across the current sources.
a)

b)

c)

d)

e)

Solution

In each case, the current source is parallel with a voltage source. Therefore, the voltage across the current source is equal to the voltage of the voltage source, regardless of other elements.

# Problem 1-4: Elements, Nodes, Loops and Branches

How many elements / nodes / loops / branches does the following circuit have?

Solution
8 elements
6 nodes, as shown:

# Problem 1-3: Using Power and Conductance

Determine the resistance of the resistor, $I$ and $V$.

# Problem 1-2: Power and Conductance of Resistors

Determine the power absorbed by the resistors, the conductance of the resistors and $V$.

# Problem 1-1: Power of Elements

Find the power of each element. Which one is supplying power and which one is absorbing it?

Solution

a)  Passive sign convention, $P = V \times I = -8 W < 0$ supplying power.