Physics is the science that studies matter, energy, motion, and the fundamental forces governing the natural world. It explains how objects move, how heat and sound travel, how light behaves, and how electricity and magnetism operate. From simple mechanical tools to modern scientific instruments, physics provides the principles that connect everyday phenomena with universal laws.
The study of physics begins with the properties of matter, which describe the physical characteristics of substances. Concepts such as mass, weight, volume, density, and specific gravity help classify materials and measure their behavior. Principles like Archimedes’ law and atmospheric pressure explain flotation, buoyancy, and the working of instruments such as barometers.
The branch of mechanics examines motion and forces. It explains velocity, acceleration, and Newton’s laws that govern the movement of objects. Ideas such as momentum, equilibrium, gravitation, work, power, and energy form the foundation of classical physics. These principles are applied in engineering, transportation, and everyday mechanical systems.
The study of heat explores temperature, thermal energy, and the transfer of heat. Effects of heating, change of state, and latent heat explain why substances melt, boil, or freeze. Modes of heat transfer — conduction, convection, and radiation — describe how energy moves through different media. These ideas are essential in understanding climate, engines, and household devices.
The branch of sound explains the production and propagation of sound waves. Properties such as pitch, intensity, and frequency describe how sound is perceived. Musical instruments demonstrate practical applications of vibration and resonance.
Optics studies the behavior of light. Rectilinear propagation explains shadows and image formation. Reflection and refraction describe how light interacts with surfaces and transparent materials. Spherical mirrors, lenses, and the human eye illustrate the principles behind vision and optical instruments.
The study of magnetism introduces natural and artificial magnets, their properties, and the concept of Earth as a giant magnet. Magnetism is closely linked with electricity and plays a major role in navigation and electrical devices.
Current electricity explains the flow of electric charge and its effects. Ohm’s law, electrical circuits, heating effects, lighting, and magnetic effects of current describe the functioning of electrical systems. Measurement of electrical power connects theoretical knowledge with practical energy use. Cells, both primary and secondary, serve as sources of electrical energy.
Modern applications extend to X-rays, which reveal internal structures and are widely used in medicine and industry. Physics also studies everyday instruments such as pulleys, levers, pumps, thermos flasks, telescopes, microscopes, and communication devices. These tools demonstrate how physical principles are applied to simplify work and extend human capability.
Taken together, physics presents a unified understanding of natural laws. Each topic builds logically upon the previous one, forming a systematic framework that explains both simple observations and complex technologies. A clear grasp of physics strengthens scientific reasoning and provides a foundation for advanced study and competitive examinations.