Heat and Thermodynamics

PART-A Unit-I: General Science

Previous Year Questions (PYQ) for this topic

Every TNPSC question asked from this topic, compiled as a PDF. · PDF 3.0 MB

Heat and Thermodynamics - PYQ Points

1. Laws of Thermodynamics

  • Second Law: A refrigerator and ice factory operate based on the Second Law of Thermodynamics.
  • Heat Transfer Principle: Without doing external work, heat cannot be transferred from a lower temperature to a higher temperature. A refrigerator transfers heat from a lower temperature region to a higher temperature region.
  • Reversibility: The transition from normal state to superconducting state is reversible according to thermodynamics.

2. Modes of Heat Transfer

  • Convection: Land breeze, sea breeze, and trade winds are formed due to convection.
  • In Solids: In transparent solids, heat transfer occurs through conduction and radiation.

3. Pressure Cooker

Food cooks faster in a pressure cooker than in an ordinary vessel.
Reason: Increased pressure raises the boiling point of water.
• In a pressure cooker, the boiling point of water is T > 100°C.

4. Properties of Ice

  • Latent Heat of Fusion: Snow on mountains does not melt all at once because of its high latent heat of fusion.
  • Change in Volume: Due to partial collapse of its tetrahedral crystal structure, the volume of ice

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