भौतिकी: मूल अवधारणाएँ

• Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force.
• Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves.

Core Concepts

• Mechanics studies the motion of macroscopic objects, such as projectiles, vehicles, and astronomical bodies.
• Thermodynamics studies heat and its relation to other forms of energy and work.
• Electromagnetism studies the interactions of electric currents and magnetic fields.
• Optics studies the behavior of light and its interaction with matter.
• Quantum mechanics studies the behavior of matter and energy at the atomic and subatomic levels.

Mechanics

• Kinematics describes motion without considering its causes, focusing on displacement, velocity, and acceleration.
• Dynamics studies the causes of motion, introducing concepts such as force, mass, and Newton's laws of motion.
• Newton's first law states that an object remains at rest or in uniform motion unless acted upon by a net force.
• Newton's second law states that the net force on an object is equal to the mass of the object times its acceleration (F = ma).
• Newton's third law states that for every action, there is an equal and opposite reaction.
• Work is the energy transferred to or from an object by a force causing a displacement.
• Energy is the capacity to do work, and it exists in various forms, including kinetic, potential, thermal, and electromagnetic.
• The conservation of energy principle states that the total energy of an isolated system remains constant.
• Power is the rate at which work is done or energy is transferred.
• Momentum is the product of an object's mass and velocity.
• The conservation of momentum principle states that the total momentum of an isolated system remains constant.
• Angular momentum is the rotational equivalent of linear momentum.
• Torque is the rotational equivalent of force.
• Simple harmonic motion (SHM) is a type of periodic motion where the restoring force is proportional to the displacement.

Thermodynamics

• Temperature is a measure of the average kinetic energy of the particles in a system.
• Heat is the transfer of thermal energy between objects or systems due to a temperature difference.
• The zeroth law of thermodynamics states that if two systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.
• The first law of thermodynamics states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system.
• The second law of thermodynamics states that the entropy of an isolated system always increases or remains constant.
• The third law of thermodynamics states that the entropy of a system approaches a minimum value as the temperature approaches absolute zero.
• Entropy is a measure of the disorder or randomness of a system.
• Heat engines convert thermal energy into mechanical work.
• Refrigerators transfer thermal energy from a cold reservoir to a hot reservoir.

Electromagnetism

• Electric charge is a fundamental property of matter that causes it to experience a force when placed in an electromagnetic field.
• Coulomb's law describes the electrostatic force between charged particles.
• Electric field is the force per unit charge experienced by a test charge placed in the field.
• Electric potential is the electric potential energy per unit charge at a given point in space.
• Capacitance is the ability of a system to store electric charge.
• Electric current is the rate of flow of electric charge.
• Resistance is the opposition to the flow of electric current.
• Ohm's law states that the voltage across a conductor is proportional to the current through it.
• Magnetic field is a field of force produced by moving electric charges.
• Ampere's law relates the magnetic field around a closed loop to the electric current passing through the loop.
• Faraday's law of induction states that a changing magnetic field induces an electromotive force (EMF) in a circuit.
• Inductance is the property of a circuit to oppose changes in current.
• Electromagnetic waves are disturbances in electric and magnetic fields that propagate through space.

Optics

• Reflection is the change in direction of a wavefront at an interface between two different media.
• Refraction is the bending of a wavefront as it passes from one medium to another.
• Lenses are optical devices that refract light to focus or diverge it.
• Interference occurs when two or more waves overlap in space.
• Diffraction is the spreading of waves as they pass through an opening or around an obstacle.
• Polarization is the property of transverse waves that describes the direction of the oscillations.

Quantum Mechanics

• Quantum mechanics is a fundamental theory in physics that describes the physical properties of nature at the scale of atoms and subatomic particles.
• The wave-particle duality states that particles can exhibit both wave-like and particle-like properties.
• The Heisenberg uncertainty principle states that there is a fundamental limit to the precision with which certain pairs of physical properties of a particle, such as position and momentum, can be known simultaneously.
• The Schrödinger equation describes the time evolution of quantum mechanical systems.
• Quantum entanglement is a phenomenon where two or more particles become linked together in such a way that the state of one particle instantaneously influences the state of the other, regardless of the distance between them.
• Quantum field theory combines quantum mechanics with special relativity.