Question

Use the second laws of thermodynamics to explain how an incandescent bulb might be less efficient than a compact fluorescent bulb.

Answer 1

An incandescent bulb produces light that comes from the heating of a filament. A compact fluorescent bulb produces light when a substance is hit by electromagnetic radiation. Compact fluorescent bulbs are more efficient than incandescent bulbs.

The first law of thermodynamics is a version of the law of conservation of energy, adapted for thermodynamic processes. Therefore, a system with lower heat emissions would be more efficient.

The second law of thermodynamics states that the total entropy of an isolated system (the thermal energy per unit temperature that is unavailable for doing useful work) can never decrease. In our context, it means that the system with the least amount of losses would be more efficient. As a conclusion the fluorescent bulb would be more efficient.