Physics Revision

Scientific Method & Scope of Physics

Scientific Method: Systematic process of observation, hypothesis formation, experimental testing, data analysis, and theory/law formulation.

Physical Quantities & SI Units

Base Physical Quantities & SI Units: Length (m), Mass (kg), Time (s), Electric Current (A), Thermodynamic Temperature (K), Amount of…

Dimensions & Dimensional Analysis

Dimensions of Fundamental Quantities: Mass [M], Length [L], Time [T], Current [I], Temperature [θ].

Measuring Instruments & Errors

Least Count (LC): The smallest value that can be directly measured by an instrument.

Vectors & Resolution

Scalar vs Vector Quantities: Scalars possess magnitude only (mass, time, temperature, electric potential, work); Vectors possess magnitude…

Graphs & Data Interpretation

Linear Regression and Line of Best Fit: Experimental data plotted on Cartesian axes; line of best fit balances data points evenly on either…

Linear Motion & Projectile Motion

Kinematic Equations for Constant Acceleration: v = u + at, s = ut + (1/2)at², v² = u² + 2as, s = ((u + v)/2)t.

Forces & Newton’s Laws

Newton's First Law (Inertia): A body remains at rest or continues to move with constant velocity unless acted upon by a non-zero resultant…

Moments & Equilibrium

Moment (Torque) of a Force: Tendency of a force to produce rotation about a pivot; Moment τ = Force * Perpendicular distance from pivot to…

Work, Energy & Power

Work Done: W = F · s = F s cos θ; Work is scalar; Work done is positive when θ < 90°, zero when θ = 90° (e.g., centripetal force), and…

Circular Motion

Angular Kinematics: Angular displacement θ (rad), Angular velocity ω = dθ/dt (rad/s), Angular acceleration α = dω/dt (rad/s²);…

Fluid Statics

Density and Relative Density: Density ρ = m / V; Relative Density (Specific Gravity) = Density of substance / Density of pure water at 4 °C.

Fluid Dynamics

Ideal Fluid Characteristics: Steady (streamline) flow, Incompressible (constant density ρ), Non-viscous (zero internal fluid friction),…

Fluids in Motion (Hydrodynamics)

Real Fluid Flow & Viscosity: Viscous friction arises from molecular cohesive forces between adjacent shearing fluid layers; Newton's Law of…

Simple Harmonic Motion

SHM Definition: Periodic motion where acceleration is directly proportional to displacement from a fixed equilibrium position and always…

Wave Motion

Wave Classification: Mechanical waves (require a physical deformable elastic medium: sound, seismic, water) vs Electromagnetic waves (can…

Wave Phenomena (Reflection, Refraction, Diffraction, Interference)

Reflection & Refraction: Reflection: Angle of incidence equals angle of reflection; Refraction: Snell's Law n1 sin θ1 = n2 sin θ2;…

Stationary Waves & Resonance

Stationary (Standing) Wave Formation: Formed by the continuous superposition of two identical progressive waves travelling in opposite…

Sound & Doppler Effect

Characteristics of Sound: Pitch (determined by fundamental frequency f), Loudness (determined by sound intensity I and amplitude, measured…

EM Waves & LASER

Electromagnetic Spectrum: Continuous range of transverse electromagnetic waves in increasing frequency (decreasing wavelength): Radio,…

Temperature & Thermometers

Concept of Temperature and Thermal Equilibrium: Zeroth Law of Thermodynamics: If bodies A and B are each in thermal equilibrium with a…

Thermal Expansion

Linear Expansivity (α): Fractional increase in length per unit temperature rise: α = ΔL / (L0 ΔT); Final length L = L0 (1 + α ΔT).

Gas Laws & Kinetic Theory

Empirical Gas Laws: Boyle's Law: P1 V1 = P2 V2 (constant T); Charles's Law: V1 / T1 = V2 / T2 (constant P); Pressure (Gay-Lussac's) Law: P1…

Calorimetry & Specific Heat

Heat Capacity & Specific Heat Capacity: Heat Capacity C = Q / ΔT (J/K); Specific Heat Capacity c = Q / (m ΔT) (J·kg⁻¹·K⁻¹); Heat…

Latent Heat & Phase Change

Phase Changes: Isothermal processes occurring at constant temperature: Melting/Freezing, Vaporization/Condensation, Sublimation.

Heat Transfer

Mechanisms of Heat Transfer: Conduction (molecular vibration and free electron diffusion without bulk macroscopic material motion; primary…

Humidity & Vapour Pressure

Vapour Pressure Concepts: Saturated Vapour Pressure (SVP) is the equilibrium vapor pressure exerted when liquid and vapor phases are in…

Thermodynamic Processes

First Law of Thermodynamics: Conservation of energy applied to thermodynamic systems: ΔQ = ΔU + ΔW, where ΔQ is heat supplied to system, ΔU…

Newton’s Law of Gravitation

Newton's Universal Law of Gravitation: Every point mass attracts every other point mass with a force directly proportional to the product…

Gravitational Field & Field Intensity

Gravitational Field Concept: The region of space surrounding a mass in which any other mass experiences a gravitational force.

Gravitational Potential & Potential Energy

Gravitational Potential (V): Work done by an external agent in bringing a unit mass from infinity to that point without acceleration: V = -…

Orbital Motion & Satellites

Orbital Velocity (vₒ): Speed required to maintain stable circular orbit of radius r = R + h: Gravitational force provides centripetal…

Escape Velocity & Energy of Orbits

Escape Velocity (vₑ): Minimum initial speed required for a projectile launched from a planetary surface to completely escape the planet's…

Electric Charge & Coulomb’s Law

Electric Charge Properties: Two types of charge (positive and negative); Like charges repel, opposite charges attract; Quantization of…

Electric Field & Electric Field Intensity

Electric Field (E): Force per unit positive test charge placed at that point: E = F / q0 (vector quantity, units N/C or V/m).

Electric Potential & Potential Energy

Electric Potential (V): Work done by an external agent in bringing a unit positive test charge from infinity to that point without…

Electric Flux & Gauss’s Law

Electric Flux (Φ): Measure of the total number of electric field lines passing through a given surface: Φ = ∫ E · dA = E A cos θ (units…

Capacitors & Capacitance

Capacitance Definition: Ability of a conductor or system of conductors to store electric charge per unit potential difference: C = Q / V…

Electric Current & Charge Flow

Electric Current (I): Rate of flow of electric charge across a cross-section: I = dQ/dt = ΔQ/Δt (scalar quantity, SI base unit Ampere =…

Ohm’s Law, Resistance & Resistivity

Ohm's Law: At constant temperature and physical conditions, electric current flowing through a metallic conductor is directly proportional…

EMF, Internal Resistance & Cells

Electromotive Force (EMF, E): Total chemical/non-electrostatic work done per unit charge in driving electric charge completely around a…

Series & Parallel Circuits

Series Resistor Combination: Same current I passes sequentially through each resistor: Equivalent Resistance Req = R1 + R2 + R3; Total…

Kirchhoff’s Laws

Kirchhoff's First Law (Current Law / Junction Rule, KCL): The algebraic sum of currents meeting at ANY junction in an electrical circuit is…

Wheatstone Bridge & Meter Bridge

Wheatstone Bridge Circuit: Bridge network of four resistors P, Q, R, S connected in a diamond with galvanometer G across central branch and…

Potentiometer

Potentiometer Principle: A uniform resistance wire of length L carrying a constant steady current: Potential difference V across any length…

Magnetic Fields & Magnetic Force

Magnetic Field (B): Region of space wherein moving charges, electric currents, or magnetic dipoles experience magnetic forces; measured in…

Magnetic Fields of Conductors & Solenoids

Biot-Savart Law: Magnetic field element dB generated by current element I dl at displacement r: dB = (μ0 / 4π) * [(I dl × r̂) / r²] = (μ0 /…

Electromagnetic Induction

Magnetic Flux (Φ): Measure of magnetic field lines penetrating surface area A: Φ = B · A = B A cos θ (units Weber = T·m² = V·s).

Alternating Current & RMS

Sinusoidal AC Waveform: Instantaneous voltage v(t) = V0 sin(ωt) and current i(t) = I0 sin(ωt ± φ), where V0, I0 are peak amplitudes, ω = 2π…

Inductive & Capacitive Reactance

Inductive Reactance (XL): Opposition offered by an ideal inductor to AC current: XL = ω L = 2π f L (units Ohm Ω); Current LAGS voltage by…

Transformers

Transformer Principle: Static electrical device transferring AC electrical energy between two isolated circuits via mutual electromagnetic…

Generators & Motors

AC Generator (Alternator): Converts mechanical work into alternating electrical energy; armature coil rotates in magnetic field; slip rings…

Semiconductors & p–n Junctions

Intrinsic Semiconductors: Pure tetravalent crystals (Silicon, Germanium) where electrical conduction at room temperature occurs via equal…

Diodes & Rectification

Semiconductor Diode: Two-terminal p-n junction device designed to permit current flow essentially in one direction (forward bias) while…

Zener Diodes & Regulation

Zener Diode Concept: Heavily doped p-n junction diode engineered specifically to operate reliably and continuously in the reverse breakdown…

Bipolar Junction Transistors (BJT)

BJT Architecture: Three-terminal current-controlled device composed of two back-to-back p-n junctions: Emitter (E, heavily doped to inject…

Field Effect Transistors (FET/JFET/MOSFET)

Field Effect Transistor Concept: Unipolar voltage-controlled three-terminal semiconductor device where conduction current through a…

Operational Amplifiers (Op‑Amps)

Op-Amp Characteristics: High-gain direct-coupled differential voltage amplifier with two inputs: Inverting input (-) and Non-inverting…

Logic Gates & Boolean Algebra

Binary Logic States: Logic 1 (HIGH, typically +5 V in TTL logic) and Logic 0 (LOW, typically 0 V / Ground).

Flip‑Flops & Sequential Logic

Combinational vs Sequential Logic: Combinational logic outputs depend strictly on present inputs (AND, OR, full adders); Sequential logic…

Stress, Strain & Elasticity

Elasticity Concepts: Property of a material body to regain its original size and shape upon removal of deforming forces; Plasticity refers…

Young’s Modulus & Elastic Potential Energy

Young's Modulus (Y): Ratio of longitudinal tensile stress to longitudinal tensile strain within Hooke's proportional limit: Y = (F / A) /…

Viscosity & Fluid Resistance

Viscosity Concept: Internal molecular friction of a fluid that resists relative motion between adjacent shearing layers; Dynamic Viscosity…

Surface Tension & Capillarity

Surface Tension (γ): Property of a liquid surface film to behave like a stretched elastic membrane; defined as force per unit length acting…

Pressure in Fluids, Upthrust & Archimedes’ Principle

Hydrostatic Pressure Equation: Fluid at rest exerts normal pressure equally in all directions; Pressure at depth h below open surface: P =…

Fluid Dynamics (Bernoulli, Continuity, Flow Rate)

Streamline and Turbulent Flow: Streamline (laminar) flow occurs when every passing fluid particle follows identical smooth trajectories…