क्लासिकल मैकेनिक्स और ऊष्मप्रवैगिकी

Classical Mechanics

• Classical mechanics describes the motion of macroscopic objects.
• It is based on Newton's laws of motion and the concept of forces.
• Newton's first law states that an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
• Newton's second law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. (F = ma)
• Newton's third law states that for every action, there is an equal and opposite reaction.
• Classical mechanics is useful for predicting the motion of objects in everyday situations.
• Concepts within classical mechanics include:
  • Kinematics (describing motion without considering forces)
  • Dynamics (describing motion in terms of forces)
  • Energy and work
  • Momentum
  • Rotational motion
  • Oscillations

Thermodynamics

• Thermodynamics deals with the relationship between heat, work, and energy.
• Key laws in thermodynamics are the following:
  • Zeroth Law: If two systems are each in thermal equilibrium with a third, then they are in thermal equilibrium with each other.
  • First Law: Energy cannot be created or destroyed, only transferred or changed from one form to another.
  • Second Law: The total entropy of an isolated system can never decrease over time. A consequence of the second law is that spontaneous processes tend toward increasing disorder (entropy).
  • Third Law: As the temperature of a system approaches absolute zero, the entropy approaches a constant minimum value.
• Applications of thermodynamics include heat engines, refrigerators, and power plants.
• Concepts in thermodynamics include:
  • Temperature
  • Heat
  • Work
  • Internal energy
  • Entropy
  • Thermodynamic cycles

Electromagnetism

• Electromagnetism describes the interaction between electric charges and magnetic fields.
• A key concept is that electric and magnetic fields are two aspects of a single electromagnetic field.
• Electromagnetism governs phenomena such as:
  • Electric fields (created by stationary charges)
  • Magnetic fields (created by moving charges or changing electric fields)
  • Electromagnetic waves (oscillating electric and magnetic fields)
• Key laws in electromagnetism include:
  • Gauss's law for electricity
  • Gauss's law for magnetism
  • Faraday's law of induction
  • Ampère-Maxwell law
• Concepts in electromagnetism include:
  • Electric charge
  • Electric field
  • Magnetic field
  • Electromagnetic waves
  • Electromagnetic force

Modern Physics

• Modern physics encompasses theories that explain the behavior of matter and energy at the atomic and subatomic levels.
• Concepts include:
  • Special relativity: describes space and time as relative to the observer, and postulates that the speed of light is constant for all observers. Key elements include the Lorentz transformations, time dilation, length contraction, and mass-energy equivalence (E=mc²).
  • General relativity: describes gravity as a curvature of spacetime caused by mass and energy. Key elements include the curvature of spacetime by mass and energy, and the equivalence principle (gravity and acceleration are indistinguishable).
  • Quantum mechanics: describes the behavior of matter and energy at the atomic and subatomic level. Key elements include quantized energy levels, wave-particle duality, and probabilistic nature of quantum events.
• Modern physics is necessary to understand and explain phenomena that are not explained by classical physics.
• Examples of modern physics' application to technologies include lasers, transistors, and quantum computing.

Optics

• Optics is the branch of physics that deals with the behaviour and properties of light.
• It includes the study of:
  • Reflection
  • Refraction
  • Diffraction
  • Interference
  • Light as an electromagnetic wave and a particle
  • Optical instruments such as telescopes and microscopes
• Different types of optics:
  • Geometrical optics (simple ray tracing to understand images and lenses.)
  • Wave optics (using wave properties to describe, e.g. interference).

Atomic and Nuclear Physics

• Atomic physics studies the structure, properties, and behavior of atoms and ions.
• Nuclear physics studies the structure, properties, and behavior of atomic nuclei.
• Key concepts include:
  • Atomic models (Bohr model, quantum mechanical model)
  • Atomic spectra (emission and absorption lines)
  • Radioactivity
  • Nuclear reactions.

Quantum Physics

• Quantum physics is a fundamental theory in modern physics that describes the universe at the atomic and subatomic levels.
• Key concepts of quantum physics:
  • Quantization of energy and matter
  • Wave-particle duality
  • Uncertainty principle
  • Superposition
  • Entanglement

क्लासिकल मैकेनिक्स स्थूल वस्तुओं की गति का वर्णन करता है और न्यूटन के गति के नियमों पर आधारित है। ऊष्मप्रवैगिकी गर्मी, काम और ऊर्जा से संबंधित है और थर्मोडायनामिक्स के नियमों पर आधारित है। ये अवधारणाएँ भौतिकी और इंजीनियरिंग के लिए महत्वपूर्ण हैं।