The working principle of steam engine is

Options

A. digital logic
B. Super conductivity
C. Laws of thermodynamics
D. Nuclear fission

Answer

### Step-by-Step Solution:

1. **Understanding the Steam Engine**:
- A steam engine is a type of heat engine that converts heat energy into mechanical work. It operates by using steam as its working fluid.

2. **Heat Energy Conversion**:
- In a steam engine, the heat energy generated from burning fuel (like coal) is used to heat water, producing steam. This steam expands and pushes against a piston or turbine, causing it to move.

3. **Mechanical Work Production**:
- The movement of the piston or turbine is what produces mechanical work. This work can be used to drive machinery, generate electricity, or propel vehicles.

4. **Thermodynamics Involvement**:
- The operation of a steam engine is governed by the laws of thermodynamics, particularly the first and second laws. The first law deals with the conservation of energy, while the second law involves the direction of energy transfer and the concept of entropy.

5. **Conclusion**:
- Therefore, the working principle of a steam engine can be summarized as the conversion of heat energy into mechanical energy, following the principles of thermodynamics.

### Final Answer:
The working principle of a steam engine is based on the conversion of heat energy into mechanical energy, following the laws of thermodynamics.

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