**Linear expansion of solid :**

Coefficient of linear expansion (α) = L_t-L_o\over L_ot[\katex]

or L_{t} = L_{0} (1 + αt)

**Relation among the coefficients of expansion of solid :**

ɑ = β/2 = γ/3

or, β = 2ɑ and γ = 3ɑ

**Expansion of liquid :**

For a liquid kept in a container, γ_{r} = γ_{a} + γ_{g}

γ_{r} = Real Expansion

γ_{a} = Apparent Expansion

γ_{g} = Gas Expansion

**Thermal conductivity :**

The quantity of heat Q conducted through a solid bar,

Q = k.A.({θ_2 - θ_1})t\over L [\katex] where k is the thermal conductivity.

**Thermal Resistance :**

R_{th} = {1\over k} \times {L\over A}[\katex]