Question

Select the correct statement.

(a) Internal energy is a path variable

(b) Heat is a path variable

(c) Work done is a state variable

(d) Internal energy is a microscopic variable

Answer 1

Correct choice is (b) Heat is a path variable

Explanation: Internal energy corresponds to the mechanical energy of molecules. It is a state variable as it doesn’t depend on the path taken. While heat is the energy in transit, so it is a path variable. Internal energy is a thermodynamic variable and is therefore macroscopic as thermodynamics deals with bulk systems.