Padikam lessons

ORIGINAL STUDY COMPANION PADIKAM CLASS 11 | SCIENCE Physics CBSE / NCERT core lessons | Academic year 2026-27 14 chapter lessons Quick explanations, core points, exam practice and chapter-specific notation in one consistent format. Padikam explanations are independently written. Official textbooks are used as the coverage map, chapter sequence and terminology reference. PADIKAM | CBSE NCERT CLASS 11 1

Contents 01 Units and Measurements 08 Mechanical Properties of Solids 02 Motion in a Straight Line 09 Mechanical Properties of Fluids 03 Motion in a Plane 10 Thermal Properties of Matter 04 Laws of Motion 11 Thermodynamics 05 Work, Energy and Power 12 Kinetic Theory 06 System of Particles and Rotational Motion 13 Oscillations 07 Gravitation 14 Waves Study rhythm Read the quick explanation, recall the core points aloud, then answer the prompts without looking back. Use the official textbook links for full prescribed readings, activities and diagrams. Textbook and verification links

1. https://cbseacademic.nic.in/web_material/CurriculumMain27/SecPart2/Physics_SecP2_2026-27.pdf
2. https://ncert.nic.in/textbook.php
3. https://cbseacademic.nic.in/curriculum_2027.html PADIKAM | CBSE NCERT CLASS 11 2

CHAPTER 01 Units and Measurements Quick understanding Measurement connects a physical quantity with a standard unit and reports both value and uncertainty. Core points Check your learning Use SI base units and derived units consistently. Find the dimensions of gravitational constant G. Significant figures show measurement precision. Combine percentage errors in a Dimensional analysis checks equations and converts calculated quantity. units, but cannot determine numerical constants. Equation and notation Percentage error = (absolute error / measured value) × 100 [G] = M⁻¹L³T⁻² SYMBOLS AND UNITS M: mass dimension L: length dimension T: time dimension G: universal gravitational constant; [G] denotes its dimensions Percentage error: dimensionless ratio expressed as % One-line recall Use SI base units and derived units consistently. PADIKAM | CBSE NCERT CLASS 11 3

CHAPTER 02 Motion in a Straight Line Quick understanding Describe one-dimensional motion using position, displacement, velocity and acceleration. Core points Check your learning Slope of an x-t graph gives velocity. Interpret a piecewise velocity-time graph. Slope of a v-t graph gives acceleration; area gives Solve a freely falling-body problem using displacement. a sign convention. The constant-acceleration equations do not apply when acceleration varies. Equation and notation v = u + at s = ut + ½at² v² = u² + 2as SYMBOLS AND UNITS u: initial velocity (m s⁻¹) v: final velocity (m s⁻¹) a: acceleration (m s⁻²) t: time (s) s: displacement (m) One-line recall Slope of an x-t graph gives velocity. PADIKAM | CBSE NCERT CLASS 11 4

CHAPTER 03 Motion in a Plane Quick understanding Treat vectors through components and analyse projectile and circular motion. Core points Check your learning Vector addition depends on magnitude and direction. Find the resultant of two perpendicular vectors. Resolve a vector along convenient perpendicular axes. Derive time of flight and range for a projectile. Projectile horizontal motion is uniform while vertical motion has acceleration g. Equation and notation R = u² sin 2θ / g T = 2u sin θ / g a_c = v²/r SYMBOLS AND UNITS θ: projection angle R: horizontal range (m) a_c: centripetal acceleration (m s⁻²) u: initial speed (m s⁻¹) g: acceleration due to gravity (m s⁻²) T: time of flight (s) v: speed (m s⁻¹) r: circular-path radius (m) One-line recall Vector addition depends on magnitude and direction. PADIKAM | CBSE NCERT CLASS 11 5

CHAPTER 04 Laws of Motion Quick understanding Use force and momentum to explain changes in motion and interactions between bodies. Core points Check your learning Inertia is resistance to change in velocity. Draw a free-body diagram for a block on a rough incline. Net external force equals rate of change of momentum. Find tension and acceleration in a two- body system. Action and reaction act on different bodies. Equation and notation F = dp/dt For constant mass: F = ma f_s ≤ μ_sN; f_k = μ_kN SYMBOLS AND UNITS p: momentum (kg m s⁻¹) N: normal reaction (N) μ: coefficient of friction F: net force (N) m: mass (kg) t: time (s) f_s, f_k: static and kinetic friction (N) μ_s, μ_k: coefficients of friction, dimensionless One-line recall Inertia is resistance to change in velocity. PADIKAM | CBSE NCERT CLASS 11 6

CHAPTER 05 Work, Energy and Power Quick understanding Connect force acting through displacement with energy transfer and rate of doing work. Core points Check your learning Work is the scalar product of force and Use a force-displacement graph to find displacement. work. Net work changes kinetic energy. Compare power for two methods of lifting a load. Mechanical energy is conserved when only conservative forces do work. Equation and notation W = Fs cos θ K = ½mv² U = mgh P = dW/dt = F·v SYMBOLS AND UNITS W: work (J) K, U: energy (J) P: power (W) F: force (N) s: displacement (m) θ: angle between force and displacement m: mass (kg) v: speed (m s⁻¹) g: acceleration due to gravity (m s⁻²) h: height (m) t: time (s) One-line recall Work is the scalar product of force and displacement. PADIKAM | CBSE NCERT CLASS 11 7

CHAPTER 06 System of Particles and Rotational Motion Quick understanding Extend mechanics from one particle to systems, centre of mass and rotation about an axis. Core points Check your learning Centre of mass follows the net external force. Locate the centre of mass of two particles. Torque changes angular momentum. Solve a rolling body energy problem. Moment of inertia depends on mass distribution and axis. Equation and notation τ = r × F L = Iω K_rot = ½Iω² v_cm = Rω SYMBOLS AND UNITS τ: torque (N m) I: moment of inertia (kg m²) ω: angular velocity (rad s⁻¹) r: position vector from the axis (m) F: force (N) L: angular momentum (kg m² s⁻¹) K_rot: rotational kinetic energy (J) v_cm: centre-of-mass speed (m s⁻¹) R: rolling radius (m) One-line recall Centre of mass follows the net external force. PADIKAM | CBSE NCERT CLASS 11 8

CHAPTER 07 Gravitation Quick understanding Apply universal attraction to planets, satellites, potential energy and escape. Core points Check your learning Gravitational force follows an inverse-square law. Derive acceleration due to gravity at Earth’s surface. Field and potential are different: one is force per mass, the other energy per mass. Compare orbital and escape speeds. Satellite speed depends on orbital radius. Equation and notation F = Gm₁m₂/r² g = GM/r² v_o = √(GM/r) v_e = √(2GM/R) SYMBOLS AND UNITS G: universal gravitational constant M: central mass (kg) r: centre-to-centre distance (m) F: gravitational force (N) m1, m2: interacting masses (kg) g: gravitational acceleration (m s⁻²) v_o: orbital speed (m s⁻¹) v_e: escape speed (m s⁻¹) R: radius of the central body (m) G: 6.67 x 10⁻¹1 N m² kg⁻² One-line recall Gravitational force follows an inverse-square law. PADIKAM | CBSE NCERT CLASS 11 9

CHAPTER 08 Mechanical Properties of Solids Quick understanding Relate deformation to restoring force through stress, strain and elastic moduli. Core points Check your learning Stress has unit pascal; strain is dimensionless. Read a stress-strain curve. Hooke’s law holds only within the elastic limit. Find extension of a wire under load. Young, bulk and shear moduli describe different deformations. Equation and notation Young modulus Y = longitudinal stress / longitudinal strain Elastic energy density = ½ × stress × strain SYMBOLS AND UNITS Y: Young modulus (Pa) ΔL: extension (m) Stress: force per area (Pa) Strain: fractional deformation, dimensionless One-line recall Stress has unit pascal; strain is dimensionless. PADIKAM | CBSE NCERT CLASS 11 10

CHAPTER 09 Mechanical Properties of Fluids Quick understanding Explain pressure, buoyancy, flow and surface effects in liquids and gases. Core points Check your learning Pressure at equal depth in a static fluid is equal. Find efflux speed from a tank. Continuity expresses mass conservation. Explain capillary rise or aerodynamic lift. Bernoulli’s relation exchanges pressure, kinetic and gravitational energy per volume. Equation and notation P = P₀ + ρgh A₁v₁ = A₂v₂ P + ½ρv² + ρgh = constant SYMBOLS AND UNITS ρ: density (kg m⁻³) η: viscosity (Pa s) γ: surface tension (N m⁻¹) P, P₀: pressure and reference pressure (Pa) g: acceleration due to gravity (m s⁻²) h: depth or height (m) A: cross-sectional area (m²) v: fluid speed (m s⁻¹) One-line recall Pressure at equal depth in a static fluid is equal. PADIKAM | CBSE NCERT CLASS 11 11

CHAPTER 10 Thermal Properties of Matter Quick understanding Connect temperature with expansion, heat capacity, phase change and heat transfer. Core points Check your learning Temperature indicates thermal state; heat is energy Solve a calorimetry mixture problem. transferred because of temperature difference. Use linear expansion to find length During a phase change, supplied heat changes state change. rather than temperature. Conduction, convection and radiation transfer heat differently. Equation and notation Q = mcΔT Q = mL ΔL = αLΔT SYMBOLS AND UNITS c: specific heat capacity (J kg⁻¹ K⁻¹) L: latent heat (J kg⁻¹) α: linear expansion coefficient (K⁻¹) Q: heat transferred (J) m: mass (kg) ΔT: temperature change (K) ΔL: length change (m) L: latent heat (J kg⁻¹) in Q = mL; original length (m) in expansion One-line recall Temperature indicates thermal state; heat is energy transferred because of temperature difference. PADIKAM | CBSE NCERT CLASS 11 12

CHAPTER 11 Thermodynamics Quick understanding Study energy exchange between a system and surroundings through heat, work and state variables. Core points Check your learning The first law is energy conservation for thermal Analyse an isothermal or adiabatic systems. process on a P-V graph. Sign convention must be stated before calculation. Calculate work and internal-energy change. No heat engine can convert all absorbed heat into work in a cycle. Equation and notation ΔQ = ΔU + ΔW For ideal gas: PV = nRT η = W/Q_H SYMBOLS AND UNITS Q: heat supplied (J) U: internal energy (J) W: work done by system (J) η: efficiency ΔQ or q: heat supplied to the system (J) ΔU: internal-energy change (J) ΔW or w: work (J) P: pressure (Pa) V: volume (m³) n: amount of gas (mol) R: molar gas constant (J mol⁻¹ K⁻¹) T: absolute temperature (K) Q_H: heat absorbed from hot reservoir (J) One-line recall The first law is energy conservation for thermal systems. PADIKAM | CBSE NCERT CLASS 11 13

CHAPTER 12 Kinetic Theory Quick understanding Explain gas pressure and temperature through random molecular motion. Core points Check your learning Ideal-gas assumptions simplify molecular Relate rms speed to temperature. interactions. Use degrees of freedom to find molar Pressure results from momentum transfer at walls. heat capacity. Absolute temperature measures average translational kinetic energy. Equation and notation P = ⅓ρv_rms² ½m⟨v²⟩ = ³⁄₂k_BT v_rms = √(3RT/M) SYMBOLS AND UNITS k_B: Boltzmann constant v_rms: root-mean-square speed (m s⁻¹) P: pressure (Pa) ρ: gas density (kg m⁻³) m: mass of one molecule (kg) T: absolute temperature (K) R: molar gas constant M: molar mass (kg mol⁻¹) One-line recall Ideal-gas assumptions simplify molecular interactions. PADIKAM | CBSE NCERT CLASS 11 14

CHAPTER 13 Oscillations Quick understanding Model periodic motion and identify simple harmonic motion as motion with restoring acceleration proportional to displacement. Core points Check your learning Amplitude is maximum displacement; period is time Write x, v and a at a stated phase. for one cycle. Find the period of a spring or simple SHM acceleration always points toward equilibrium. pendulum. Energy shifts between kinetic and potential while total stays constant. Equation and notation x = A cos(ωt + φ) a = −ω²x T_spring = 2π√(m/k) T_pendulum = 2π√(l/g) SYMBOLS AND UNITS A: amplitude (m) ω: angular frequency (rad s⁻¹) φ: phase constant (rad) x: displacement (m) a: acceleration (m s⁻²) t: time (s) T_spring, T_pendulum: period (s) m: oscillating mass (kg) k: spring constant (N m⁻¹) l: pendulum length (m) g: acceleration due to gravity (m s⁻²) One-line recall Amplitude is maximum displacement; period is time for one cycle. PADIKAM | CBSE NCERT CLASS 11 15

CHAPTER 14 Waves Quick understanding Describe travelling disturbances, superposition, standing waves and sound. Core points Check your learning Wave speed depends on the medium, while Find harmonics in an open or closed frequency is fixed by the source. pipe. Superposition produces interference and standing Use beat frequency to compare two waves. sources. Nodes have zero displacement; antinodes have maximum displacement. Equation and notation v = fλ y = A sin(kx − ωt) f_beat = |f₁ − f₂| SYMBOLS AND UNITS λ: wavelength (m) f: frequency (Hz) k = 2π/λ: wave number (rad m⁻¹) v: wave speed (m s⁻¹) y: particle displacement (m) A: amplitude (m) x: position (m) ω: angular frequency (rad s⁻¹) t: time (s) f_beat, f₁, f₂: frequencies (Hz) One-line recall Wave speed depends on the medium, while frequency is fixed by the source. PADIKAM | CBSE NCERT CLASS 11 16