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Given are statements for certain thermodynamic variables. (A) Internal energy, volume (V) and mass (M) are extensive variables. (B) Pressure (P), temperature (T) and density (ρ) are intensive variables. (C) Volume (V), temperature (T) and density (ρ) are intensive variables. (D) Mass (M), temperature (T) and internal energy are extensive variables. Choose the correct answer from the points given below: (1) (C) and (D) only (2) (C) and (A) only (3) (A) and (B) only (4) (B) and (C) only

1. (C) and (D) only
2. (C) and (A) only
3. (A) and (B) only
4. (B) and (C) only

Correct answer: (A) and (B) only

Solution

Statements (A) and (B) correctly identify extensive and intensive variables: internal energy, volume, and mass are extensive because they depend on the amount of substance, while pressure, temperature, and density are intensive as they do not depend on the quantity of material.

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