The efficiency of a coal power plant is typically around 33-40%, while the efficiency of an internal combustion engine in a car is around 20-30%. This means that a coal power plant is generally more efficient at converting the energy in coal into electricity than an internal combustion engine is at converting the energy in gasoline into mechanical energy to power a car. However, it's important to note that both coal power plants and internal combustion engines are sources of greenhouse gas emissions, and efforts are being made to improve the efficiency and reduce the environmental impact of both technologies. **

The efficiency of a battery is not solely dependent on its internal resistance. Other factors that can affect battery efficiency include its chemical composition, temperature, and the rate of discharge. The chemical composition of the battery determines its energy density and how efficiently it can convert chemical energy into electrical energy. Temperature can also impact a battery's efficiency, as extreme temperatures can affect the chemical reactions within the battery. Additionally, the rate of discharge can impact a battery's efficiency, as higher discharge rates can lead to increased internal resistance and reduced overall efficiency. **

It will never be possible to build an internal combustion engine with the same efficiency as a good electric motor because of the fundamental differences in their design and operation. Internal combustion engines rely on the combustion of fuel to generate power, which inherently leads to energy loss through heat and friction. On the other hand, electric motors convert electrical energy directly into mechanical energy with minimal energy loss. Additionally, electric motors have fewer moving parts and require less maintenance, making them inherently more efficient than internal combustion engines. Finally, electric motors can be powered by renewable energy sources, further increasing their overall efficiency compared to internal combustion engines. **