- ⭐ – Most used in JEE
- ⚠️ – Common Mistake
- 💡 – Memory Hint
Temperature & Heat
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Heat | [Q = mc\Delta T] | [Q] = heat, [m] = mass, [c] = specific heat, [\Delta T] = temperature change | J | Basic relation ⭐ |
| Heat Capacity | [C = \dfrac{Q}{\Delta T}] | [C] = heat capacity | J/K | For whole body |
| Specific Heat | [c = \dfrac{Q}{m\Delta T}] | — | J/kg·K | Depends on material |
💡 Memory Hint:
Heat required ∝ mass × temperature change
Thermal Expansion
Linear Expansion
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Change in Length | [\Delta L = \alpha L \Delta T] | [\alpha] = coefficient of linear expansion, [L] = original length | m | Most basic ⭐ |
Area Expansion
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Change in Area | [\Delta A = 2\alpha A \Delta T] | [A] = area | m² | Coefficient = [2\alpha] |
Volume Expansion
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Change in Volume | [\Delta V = \gamma V \Delta T] | [\gamma] = volume coefficient | m³ | [\gamma \approx 3\alpha] ⭐ |
💡 Memory Hint:
Linear : Area : Volume → 1 : 2 : 3
Anomalous Expansion of Water
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Maximum Density | Occurs at [4^\circ C] | — | — | Water behaves abnormally ⚠️ |
💡 Memory Hint:
Water is densest at 4°C
Calorimetry
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Heat Balance | [\text{Heat lost} = \text{Heat gained}] | — | — | No heat loss to surroundings ⭐ |
| Mixing Formula | [m_1 c_1 (T_1 – T) = m_2 c_2 (T – T_2)] | [T] = final temperature | J | Very important ⭐ |
💡 Memory Hint:
Hot loses = Cold gains
Change of State (Latent Heat)
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Latent Heat | [Q = mL] | [L] = latent heat | J | No temperature change ⭐ |
| Fusion | [Q = mL_f] | [L_f] = latent heat of fusion | J | Solid ↔ liquid |
| Vaporization | [Q = mL_v] | [L_v] = latent heat of vaporization | J | Liquid ↔ gas |
💡 Memory Hint:
Phase change → temperature constant
Heat Transfer
Conduction
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Heat Flow | [Q = \dfrac{kA\Delta T}{L} \cdot t] | [k] = thermal conductivity, [A] = area, [L] = length, [t] = time | J | Fourier’s law ⭐ |
💡 Memory Hint:
More area → more heat flow
Radiation
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Stefan’s Law | [P = \sigma A T^4] | [\sigma] = Stefan constant | W | Very important ⭐ |
| Net Radiation | [P = \sigma A (T_1^4 – T_2^4)] | — | W | Surroundings effect ⚠️ |
💡 Memory Hint:
Radiation ∝ T⁴
Newton’s Law of Cooling
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Cooling Law | [\dfrac{dT}{dt} \propto (T – T_s)] | [T_s] = surroundings temperature | — | Valid for small ΔT ⭐ |
💡 Memory Hint:
Faster cooling when temperature difference is high
Thermal Resistance
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Thermal Resistance | [R = \dfrac{L}{kA}] | — | K/W | Opposes heat flow |
| Series Combination | [R_{eq} = R_1 + R_2] | — | K/W | Like resistors ⭐ |
| Parallel Combination | [\dfrac{1}{R_{eq}} = \dfrac{1}{R_1} + \dfrac{1}{R_2}] | — | K/W | Alternate path |
💡 Memory Hint:
Heat flow ↔ electric current analogy