Physics studies matter, energy, and their interactions. Class 9th introduces basic physics concepts like motion and force. Physics forms foundation for later advanced topics
Renewable energy consumption will increase nearly 60% by 2030. Renewables will reach nearly 20% of final energy consumption by 2030. Electricity generation from renewables will account for over three-quarters of growth
Thermodynamics studies energy transformation and heat-matter relationships. System is everything within boundary, surroundings are everything outside. Heat is energy transmitted between objects due to temperature difference. Work done depends on system's initial/final states and chosen path
Thermodynamics studies heat, work, temperature, and energy relationships. Count Rumford discovered heat generation in cannon boring in 1798. Sadi Carnot introduced heat-engine cycle concept in 1824. Rudolf Clausius developed first and second laws of thermodynamics
Entropy measures spontaneous changes in thermodynamic systems. Term introduced by Rudolf Clausius in mid-19th century. Entropy predicts irreversible processes despite energy conservation. Boltzmann defined entropy as number of possible microscopic configurations
Energy cannot be created or destroyed, only transformed. Heat and thermodynamic work are two main forms of energy transfer. Internal energy is a property of a system, not just heat or work