# NEET Physics Thermodynamics Questions Solved

A Carnot's engine used first an ideal monoatomic gas then an ideal diatomic gas. If the source and sink temperature are 411°C and 69°C respectively and the engine extracts 1000 J of heat in each cycle, then area enclosed by the PV diagram is -

(1) 100 J

(2) 300 J

(3) 500 J

(4) 700 J

(3) $\eta =1-\frac{{T}_{2}}{{T}_{1}}=1-\frac{\left(273+69\right)}{\left(273+411\right)}=0.5$

⇒ Work done $=\eta ×Q=0.5×1000=500\text{\hspace{0.17em}}J$

Difficulty Level:

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