Question

Consider a nuclear power plant, its transmission lines, and everything it provides energy to as a closed system. Which of the following is then true for the system?

Answer 1

Energy would be conserved within the system. What are the choices?

Answer 2

@eashmore The thermal energy within the system stays constant.

The mechanical energy within the system stays constant.

The nuclear energy within the system stays constant.

The total energy within the system stays constant.

Answer 3

Conservation of energy, broadly defined.

Answer 4

@douglaswinslowcooper is correct.

Energy, as the loose "property of matter," is always conserved by the Law of Conservation of Energy

For this law to hold, energy is usually always changing forms or types.

For this example, nuclear energy is converted into heat to boil the heavy water in the reactor. This steam is then converted into mechanical energy in a steam turbine. The mechanical energy in the steam turbine is converted into electrical energy in a generator. The electrical energy is converted into light and heat energy in a lightbulb in your lamp plugged into a power outlet.

Even through all these conversions, the energy within the box we drew around the power-plant and everything hooked up to it remains constant.

The ideas and theories behind studying and understanding this flow and transformation of energy is presented in Thermodynamics.