A carnot engine takes in 3 xx 10^6 cal of heat from source at 627^@ C and gives it to a sink at 27^@ C. The work done by the engine would be _____ (J=4.2 J/cal).

A carnot engine takes in 3 xx 10^6 cal of heat from source at 627^@ C

1.	A carnot engine takes in 3 xx 10^6 cal of heat from source at 627^@ C and gives it to a sink at 27^@ C. The work done by the engine would be _____ (J=4.2 J/cal).
Answer» zero `4.2xx10^6` J `8.4xx10^6` J `16.8 xx10^6` J Solution :Temperature of HEAT source `T_1`=273+627=900 K Temperature of heat sink `T_2`= 273+27 = 300 K Heat absorbs from source , `Q_1=3xx10^6` cal `=4.2xx3xx10^6` Joule `rArr` The EFFICIENCY of CARNOT engine, `eta=1-T_2/T_1` `=1-300/900` `=600/900` `=2/3` Now efficiency of carnot engine `eta=W/Q_1` `therefore W=eta Q_1` `=2/3xx4.2xx3xx10^6` `=8.4xx10^6` J