The four thin coiled wires have resistance of 10 ohms, 20 ohms, 30 ohms and 40 ohms. The battery has a voltage of 20 v and the internal resistance of 20 ohms. Please show how to make a heater with the greatest possible heating power.
Solution. Posted on Saturday, December 20, 2014.
In order to obtain maximum external power from a source with a internal resistance, the external resistance (load) must be equal to the internal resistance of the source.
Thereby, we have to connect the four thin coiled wires by this way
Finally, we have the external resistance equals 20 ohms and our heater will produce the greatest possible heating power.