Answer:
A practical machine cannot be 100 percent efficient because of inherent energy losses, primarily due to friction, heat dissipation, and other resistive forces. These losses occur in various forms, such as:
1. **Friction:** Moving parts within the machine generate friction, which converts some of the useful energy into heat.
2. **Heat Dissipation:** Energy is lost as heat to the surroundings due to inefficiencies in energy transfer processes.
3. **Electrical Resistance:** In electrical machines, resistance in wires and components causes energy loss in the form of heat.
4. **Air Resistance:** Machines that move through air or fluid encounter resistance, which also leads to energy losses.
These factors ensure that no machine can achieve 100 percent efficiency, as some energy will always be lost to the surroundings in practical applications.
