# 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.

a)

b)

c)

d)

e)

## 5 thoughts on “Problem 1-13: Voltage of A Current Source”

1. Chris Cole

Dr. Li -

I am trying to understand circuit d better. Why is it that the 6 ohm resister doesn't conduct? What direction does the current flow through the battery? Can it be redrawn in a way making it clearer?

Thank you.

1. Dr. Yaz Z. Li

The $latex 6 \Omega$ is short circuited. Then the all portion of current passes through the wire which is short circuiting the $latex 6 \Omega$. When two sides of a resistor are connected to each other, the voltage across the resistor is zero. Therefore, the Ohm's law also implies that the current is zero: $V=RI=0 \to I=0$.
The current of $latex 3 \Omega$ is $latex \frac{3V}{3 \Omega}=1 A$ from the top to the bottom. The current of the current source is $latex 2 A$ from the top to the bottom. So, the current of the voltage source is $latex 2 A + 1 A$ from bottom to the top, i.e. from the negative terminal to the positive one.

2. wngzo

thanks alot for sharing your knowledge with us....
do me a favor?
what is meant by
1) voltage controlled current source and
2) current controlled voltage source ,
3)voltage controlled voltage source and also
4) current controlled current source?