A good measure is its internal resistance. If the internal resistance was 1 ohm, the output voltage would fall by 1 volt for every amp of current taken. So - how low is the internal resistance? is a good question to find out how strong the source is.
load test
load test
voltmeter
voltmeter
Consider a battery for a moment. A battery can be a source or sink type of power source. A light bulb would be considered a source current. When a battery or other item is being charged is it considered a sinking source.
The battery is the voltage or power source, the wires form the conductor.
The battery is the voltage or power source, the wires form the conductor.
battery
Battery
Car battery.
The source in electric cuircuit is having sex with a woman.
Your phone has a battery behind back cover as a power source.