# NEET Physics Thermodynamics Questions Solved

Unit mass of a liquid with volume V1 is completely changed into a gas of volume V2 at a constant external pressure P and temperature T. If the latent heat of evaporation for the given mass is L, then the increase in the internal energy of the system is -

(1) Zero

(2) $P\left({V}_{2}-{V}_{1}\right)$

(3) $L-P\left({V}_{2}-{V}_{1}\right)$

(4) L

(3) $\Delta Q=\Delta U+P\Delta V$

mL = ΔU + P(V2V1)

⇒ ΔU = LP (V2V1) (∵ m = 1)

Difficulty Level:

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