# Homework Help: Voltage or Current Source?

1. Jan 25, 2016

### Marcin H

1. The problem statement, all variables and given/known data
Check picture

2. Relevant equations
V=IR

3. The attempt at a solution
I thought I had this right, but then I started thinking about it and I'm not sure anymore. My thought was since the voltage was changing and the current was constant, that the source was a voltage source. I kinda thought of it as you changing the voltage on a power supply or something keeping the current constant. Is that right? I feel like it's not.

2. Jan 25, 2016

### Staff: Mentor

Ideal independent supplies are generally specified to produce a single fixed value. A voltage supply produces a fixed voltage, while a current supply produces a fixed current. Variable power supplies are not the same thing, being more a version of a controlled source with other bells and whistles for convenience and safety.

An ideal voltage supply will produce a given fixed voltage no matter what. It will produce any amount of current required in order to accomplish this.

An ideal current supply will produce a given fixed current no matter what. It will produce any amount of voltage required in order to accomplish this.

3. Jan 25, 2016

### Marcin H

Hmm. Ok. Thanks for clarifying!