ICSE Class 10 Physics: Heat & Calorimetry — Complete Notes 2026

Heat and Temperature

• Heat is energy in transit; temperature measures degree of hotness; SI unit kelvin (K)
• Celsius to Kelvin: K = °C + 273; Fahrenheit conversion
• Thermometers: liquid-in-glass, clinical, maximum-minimum

Specific Heat Capacity

• Q = mcΔT; c = specific heat capacity (J kg⁻¹ K⁻¹)
• Water has highest specific heat (4200 J/kg/K) — moderates climate
• Calorimetry: heat lost by hot body = heat gained by cold body (no loss)

Latent Heat

• Latent heat of fusion L_f: heat absorbed to melt at constant temperature
• Latent heat of vaporisation L_v: heat absorbed during evaporation; L_v > L_f always
• Q = mL; calculate ice melting or steam condensing

Change of State

• Melting, freezing, boiling, condensation, sublimation, deposition
• Plateau on cooling curve: temperature constant during phase change
• Effect of pressure on boiling point: pressure cooker principle

Thermal Expansion

• Linear expansion: ΔL = αLΔT; area and volume expansion coefficients
• Anomalous expansion of water: maximum density at 4°C; why pipes burst
• Bimetallic strip: unequal expansion causes bending; used in thermostats

Modes of Heat Transfer

• Conduction: particle vibration in solids; thermal conductivity k
• Convection: bulk movement of fluid; sea breeze, atmospheric circulation
• Radiation: electromagnetic waves; no medium needed; Stefan-Boltzmann law

Numericals — Heat

• Find final temperature when 200 g of water at 80°C is mixed with 100 g at 20°C
• Heat needed to convert 50 g ice at −10°C fully to steam at 100°C
• Thermal expansion: gap left in railway tracks; calculate minimum gap needed