Find the dimensions of
A. the specific heat capacity c,
B. the coefficient of linear expansion α and
C. the gas constant R.
Some of the equations involving these quantities are
and ![]()
A. Specific heat capacity is defined as the amount of heat required to raise the temperature of a body of mass 1 gm by 1 K.
Specific heat capacity can be calculated from the relation -
Heat energy (Q) = mass (m) × specific heat capacity(c) × temperature gradient(ΔT)
From here ![]()
Dimensions of Q = [ML2T-2]
Dimensions of m = [M]
Dimensions of ΔT = [K]
Dimensions of c = ![]()
B. Coefficient of linear expansion is defined as the rate of change of length of a body when heat is applied to it per unit temperature change.
Coefficient of linear expansion (α) can be calculated from the relation –
Length at time t (lt) = initial length (l0)[1 + α(ΔT)]
where ΔT is the change in temperature
From the relation we have ![]()
Dimensions of lt = [L]
Dimensions of l0 = [L]
Dimensions of ΔT = [K]
Dimensions of α = ![]()
C. Universal Gas constant is the constant of proportionality that appears in the ideal gas equation. It is also equal to the Boltzmann Constant (Kb). It is a physical constant that gives the kinetic energy of a gas for different temperatures.
Gas constant (R) can be found out from the ideal gas equation –
Pressure(P) × Volume(V) = moles(n)× UGC (R) × Temperature (T)
From the relation ![]()
Dimensions of P = [ML-1T-2]
Dimensions of V = [L3]
Dimensions of n = [mol]
Dimensions of T = [K]
Dimensions of R = ![]()