616 marks

Electrostatics

This chapter deals with electric charges, fields, potential, capacitance, and related concepts.

42 Topics

55h prep

5.3% subject weight

42 Topics

Electric charges

2m1/10

📌 Key FormulaTwo types: positive and negative, like charges repel, unlike attract.

Conservation of charge

2m1/10

📌 Key FormulaTotal charge of an isolated system remains constant.

Coulomb's law-forces between two point charges

2m2/10

📌 Key FormulaF = k q₁q₂/r², where k = 1/(4πε₀)

Forces between multiple charges

2m2/10

📌 Key FormulaSuperposition principle: net force = vector sum of individual forces.

Superposition principle and continuous charge distribution

2m3/10

📌 Key FormulaElectric field due to continuous distribution: E = ∫ dE.

Electric field due to a point charge

2m2/10

📌 Key FormulaE = kq/r² (direction radial)

Electric field lines

2m1/10

📌 Key FormulaStart from positive, end at negative, tangent gives direction.

Electric dipole

2m1/10

📌 Key FormulaDipole moment p = qd, direction from - to +.

Electric field due to a dipole

2m3/10

📌 Key FormulaOn axial line: E = 2kp/r³, on equatorial line: E = kp/r³

Torque on a dipole in a uniform electric field

2m2/10

📌 Key Formulaτ = p × E, τ = pE sin θ

Electric flux

2m2/10

📌 Key Formulaφ = E·A (for uniform field), φ = ∫ E·dA (general)

Gauss's law and its applications to find field due to infinitely long uniformly charged straight wire

2m3/10

📌 Key Formulaφ = q_enclosed/ε₀. For wire: E = λ/(2πε₀r)

Gauss's law and its applications to find field due to uniformly charged infinite plane sheet

2m3/10

📌 Key FormulaE = σ/(2ε₀)

Gauss's law and its applications to find field due to uniformly charged thin spherical shell

2m3/10

📌 Key FormulaInside: E=0, outside: E = kQ/r²

Electric potential and its calculation for a point charge

2m2/10

📌 Key FormulaV = kq/r

Electric dipole and system of charges

2m3/10

📌 Key FormulaV = Σ kqᵢ/rᵢ, potential due to dipole V = kp cos θ/r²

Equipotential surfaces

2m1/10

📌 Key FormulaSurface with constant potential, E ⟂ to equipotential surface.

Electrical potential energy of a system of two point charges in an electrostatic field

2m2/10

📌 Key FormulaU = k q₁q₂/r

Conductors and insulators

2m1/10

📌 Key FormulaConductors allow charge flow, insulators do not.

Dielectrics and electric polarization

2m2/10

📌 Key FormulaDielectrics are insulators, polarization due to electric field.

Capacitor

2m1/10

📌 Key FormulaQ = CV

The combination of capacitors in series and parallel

2m2/10

📌 Key FormulaSeries: 1/C_eq = Σ 1/Cᵢ, Parallel: C_eq = Σ Cᵢ

Capacitance of a parallel plate capacitor with and without dielectric medium between the plates

2m2/10

📌 Key FormulaWithout dielectric: C₀ = ε₀A/d, With dielectric: C = κC₀

Energy stored in a capacitor

2m2/10

📌 Key FormulaU = ½CV² = Q²/(2C) = ½QV

Thermal expansion of solids

2m2/10

📌 Key FormulaΔL = L₀ α ΔT

Thermal expansion of liquids

2m2/10

📌 Key FormulaΔV = V₀ γ ΔT

Thermal expansion of gases

2m2/10

📌 Key FormulaIdeal gas law, PV = nRT

Heat conduction in one dimension

2m2/10

📌 Key FormulaQ/t = kA(ΔT/L)

Calorimetry

2m2/10

📌 Key FormulaHeat lost = Heat gained.

Latent heat

2m1/10

📌 Key FormulaQ = mL

Elementary concepts of convection and radiation

2m1/10

📌 Key FormulaHeat transfer mechanisms.

Newton’s law of cooling

2m3/10

📌 Key FormuladT/dt = -k(T - T₀)

Specific heats (Cv and Cp for monoatomic and diatomic gases)

2m3/10

📌 Key FormulaC_v = f/2 R, C_p = C_v + R, γ = C_p/C_v

Isothermal and adiabatic processes

2m3/10

📌 Key FormulaIsothermal: PV = constant, Adiabatic: PV^γ = constant

Bulk modulus of gases

2m2/10

📌 Key FormulaB = -ΔP/(ΔV/V)

Equivalence of heat and work

2m1/10

📌 Key FormulaMechanical equivalent of heat J.

First law of thermodynamics and its applications (only for ideal gases)

2m2/10

📌 Key FormulaΔU = Q - W

Blackbody radiation

2m1/10

📌 Key FormulaIdeal absorber and emitter.

Absorptive and emissive powers

2m2/10

📌 Key FormulaKirchhoff's law: α = e

Kirchhoff’s law

2m1/10

📌 Key FormulaGood absorber is good emitter.

Wien’s displacement law

2m2/10

📌 Key Formulaλ_max T = constant

Stefan’s law

2m2/10

📌 Key FormulaE = σT⁴

616 marks

Electrostatics

This chapter deals with electric charges, fields, potential, capacitance, and related concepts.

42 Topics

55h prep

5.3% subject weight

42 Topics

Electric charges

2m1/10

📌 Key FormulaTwo types: positive and negative, like charges repel, unlike attract.

Conservation of charge

2m1/10

📌 Key FormulaTotal charge of an isolated system remains constant.

Coulomb's law-forces between two point charges

2m2/10

📌 Key FormulaF = k q₁q₂/r², where k = 1/(4πε₀)

Forces between multiple charges

2m2/10

📌 Key FormulaSuperposition principle: net force = vector sum of individual forces.

Superposition principle and continuous charge distribution

2m3/10

📌 Key FormulaElectric field due to continuous distribution: E = ∫ dE.

Electric field due to a point charge

2m2/10

📌 Key FormulaE = kq/r² (direction radial)

Electric field lines

2m1/10

📌 Key FormulaStart from positive, end at negative, tangent gives direction.

Electric dipole

2m1/10

📌 Key FormulaDipole moment p = qd, direction from - to +.

Electric field due to a dipole

2m3/10

📌 Key FormulaOn axial line: E = 2kp/r³, on equatorial line: E = kp/r³

Torque on a dipole in a uniform electric field

2m2/10

📌 Key Formulaτ = p × E, τ = pE sin θ

Electric flux

2m2/10

📌 Key Formulaφ = E·A (for uniform field), φ = ∫ E·dA (general)

Gauss's law and its applications to find field due to infinitely long uniformly charged straight wire

2m3/10

📌 Key Formulaφ = q_enclosed/ε₀. For wire: E = λ/(2πε₀r)

Gauss's law and its applications to find field due to uniformly charged infinite plane sheet

2m3/10

📌 Key FormulaE = σ/(2ε₀)

Gauss's law and its applications to find field due to uniformly charged thin spherical shell

2m3/10

📌 Key FormulaInside: E=0, outside: E = kQ/r²

Electric potential and its calculation for a point charge

2m2/10

📌 Key FormulaV = kq/r

Electric dipole and system of charges

2m3/10

📌 Key FormulaV = Σ kqᵢ/rᵢ, potential due to dipole V = kp cos θ/r²

Equipotential surfaces

2m1/10

📌 Key FormulaSurface with constant potential, E ⟂ to equipotential surface.

Electrical potential energy of a system of two point charges in an electrostatic field

2m2/10

📌 Key FormulaU = k q₁q₂/r

Conductors and insulators

2m1/10

📌 Key FormulaConductors allow charge flow, insulators do not.

Dielectrics and electric polarization

2m2/10

📌 Key FormulaDielectrics are insulators, polarization due to electric field.

Capacitor

2m1/10

📌 Key FormulaQ = CV

The combination of capacitors in series and parallel

2m2/10

📌 Key FormulaSeries: 1/C_eq = Σ 1/Cᵢ, Parallel: C_eq = Σ Cᵢ

Capacitance of a parallel plate capacitor with and without dielectric medium between the plates

2m2/10

📌 Key FormulaWithout dielectric: C₀ = ε₀A/d, With dielectric: C = κC₀

Energy stored in a capacitor

2m2/10

📌 Key FormulaU = ½CV² = Q²/(2C) = ½QV

Thermal expansion of solids

2m2/10

📌 Key FormulaΔL = L₀ α ΔT

Thermal expansion of liquids

2m2/10

📌 Key FormulaΔV = V₀ γ ΔT

Thermal expansion of gases

2m2/10

📌 Key FormulaIdeal gas law, PV = nRT

Heat conduction in one dimension

2m2/10

📌 Key FormulaQ/t = kA(ΔT/L)

Calorimetry

2m2/10

📌 Key FormulaHeat lost = Heat gained.

Latent heat

2m1/10

📌 Key FormulaQ = mL

Elementary concepts of convection and radiation

2m1/10

📌 Key FormulaHeat transfer mechanisms.

Newton’s law of cooling

2m3/10

📌 Key FormuladT/dt = -k(T - T₀)

Specific heats (Cv and Cp for monoatomic and diatomic gases)

2m3/10

📌 Key FormulaC_v = f/2 R, C_p = C_v + R, γ = C_p/C_v

Isothermal and adiabatic processes

2m3/10

📌 Key FormulaIsothermal: PV = constant, Adiabatic: PV^γ = constant

Bulk modulus of gases

2m2/10

📌 Key FormulaB = -ΔP/(ΔV/V)

Equivalence of heat and work

2m1/10

📌 Key FormulaMechanical equivalent of heat J.

First law of thermodynamics and its applications (only for ideal gases)

2m2/10

📌 Key FormulaΔU = Q - W

Blackbody radiation

2m1/10

📌 Key FormulaIdeal absorber and emitter.

Absorptive and emissive powers

2m2/10

📌 Key FormulaKirchhoff's law: α = e

Kirchhoff’s law

2m1/10

📌 Key FormulaGood absorber is good emitter.

Wien’s displacement law

2m2/10

📌 Key Formulaλ_max T = constant

Stefan’s law

2m2/10

📌 Key FormulaE = σT⁴