JEE Main · 2021 · 16 Mar 2021 · Shift 1 · Heat & Thermodynamics

In thermodynamics, heat and work are :

(A)Point functions
(B)Extensive thermodynamic state variables
(C)Path functions✓ Correct
(D)Intensive thermodynamic state variables

Answer: (C)

Solution

A system in a given state has a definite internal energy, but no definite amount of heat or work: two different processes joining the same pair of states exchange different amounts of each, and only the difference

Δ U = Q - W

comes out the same. Quantities whose values depend on the route taken rather than on the end states alone are path functions, and they cannot be listed among the variables that describe a state.
Heat and work are path functions.

JEE Main · 2021 · 16 Mar 2021 · Shift 1 · Single correct option

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