Electric Circuits - Mission EC3 Detailed Help


A certain electrical circuit contains a battery, wires and a light bulb. If potential energy is gained by charges at the battery, charges lose potential energy ____.


 
In a sense, circuits are all about energy. Energy is introduced into the circuit by the battery. The battery acts as a charge pump in a circuit, moving charge between terminals so as to supply an electric potential difference across the two ends of a circuit. It serves an analogous role as the water pump in a water circuit. The battery moves the charge from low energy to high energy much like a water pump moves water from low energy to high energy. Both processes require the input of energy to the system. If the battery is the energy input location of a circuit, then the energy output is the light bulb. As charge moves through the light bulb, its electric potential energy is dramatically decreased as light energy is produced. In this sense, circuits are all about energy - energy in at the battery and energy out at the light bulb.
 
The above discussion ignores the fact that life does not always turn out as ideally as dreamed. The lives of charge flow in electric circuits is plagued the reality of inefficiency. Light bulbs don't simply produce light energy; they also get hot and produce thermal energy. This represents a waste of energy as the bulb's lack of efficiently results in the production of an unintended form of energy. Also, the wires are not exactly efficient conduits through which charge flows. Wires heat up as well and cause a very small loss of energy.