Physics Notes For Competitive Exams

SI Units: The International System of Units (SI) is the modern form of the metric system and the most widely used system of measurement. Key units include the meter (m) for length, kilogram (kg) for mass, second (s) for time, ampere (A) for electric current, kelvin (K) for temperature, mole (mol) for amount of substance, and candela (cd) for luminous intensity.
Measurements: Involves techniques and instruments used to measure physical quantities accurately and precisely, including tools like rulers, balances, thermometers, and voltmeters.

Magnetism: Study of magnetic fields and forces, magnetic materials, and their applications. Key concepts include magnetic poles, electromagnetism, and magnetic flux.
Electricity: Study of electric charge, electric fields, electric potential, current, resistance, and circuits. Includes concepts like Ohm’s Law, Kirchhoff’s Laws, and Coulomb’s Law.

Forces: Any interaction that, when unopposed, will change the motion of an object. Types of forces include gravitational, electromagnetic, strong nuclear, and weak nuclear forces.
Gravity: A force of attraction between masses. Newton’s Law of Universal Gravitation and Einstein’s General Theory of Relativity are key theories explaining gravity.

Kinematics: Study of motion without considering its causes, including concepts like velocity, acceleration, and displacement.
Dynamics: Study of the forces and their effects on motion. Newton’s Laws of Motion are fundamental here.

Work: Product of the force applied to an object and the distance over which it is applied. Measured in joules (J).
Power: Rate at which work is done or energy is transferred. Measured in watts (W).
Energy: The capacity to do work. Types include kinetic, potential, thermal, chemical, and nuclear energy.
Temperature: Measure of the average kinetic energy of the particles in a substance. Measured in degrees Celsius (°C), Fahrenheit (°F), or Kelvin (K).

Optics: Study of light and its interactions with matter. Includes reflection, refraction, diffraction, and interference. Key concepts include lenses, mirrors, and the behavior of light waves.

Newton’s Laws of Motion: Three fundamental laws describing the relationship between the motion of an object and the forces acting on it.
Conservation Laws: Principles like the conservation of energy, momentum, and charge, which state that certain quantities remain constant in a closed system.
Thermodynamics: Laws governing the relations between different forms of energy and heat, including the First and Second Laws of Thermodynamics.

Wave-Particle Duality: Concept in quantum mechanics that every particle or quantum entity can be described as both a particle and a wave.
Quantum Mechanics: Study of physical phenomena at microscopic scales, where the action is on the order of the Planck constant.
Relativity: Einstein’s theories of Special and General Relativity, which describe the behavior of objects in high-speed motion and in the presence of gravitational fields.

Scalar: A physical quantity that has only magnitude (e.g., temperature, mass).
Vector: A physical quantity that has both magnitude and direction (e.g., velocity, force).
Amplitude: Maximum extent of a vibration or oscillation, measured from the position of equilibrium.
Frequency: Number of occurrences of a repeating event per unit of time.