A DC source of EMF E volts and internal resistance R ohms is connected to a variable load and it is adjusted such that the load absorbs maximum power from the source. The maximum power delivered from the source to the load is:
1
\(\rm \frac{E^2}{2R}\)
2
\(\rm \frac{E^2}{R}\)
3
\(\rm \frac{2E^2}{R}\)
4
\(\rm \frac{E^2}{4R}\)