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An ideal gas heat engine operates in Carnot cycle between `227^(@)C` and `127^(@)C`. It absorbs `6 x 10^(4) cals` of heat at higher temperature. Amount of heat converted to work isA. `2.4 xx 10^(4) cal`B. `6 xx 10^(4) cal`C. `1.2 xx 10^(4) cal`D. `4.8 xx 10^(4) cal` |
Answer» Correct Answer - C We have `Q/T` = consta nt `implies (Q_2)/(Q_1)=(T_2)/(T_1)` Given, `Q_(1)=6xx10^(4) cal`, `T_(1)=227+273=500K` `T_(2) = 127+273 = 400K` `:. (Q_2)/(6xx10^4)= 400/500` `implies Q_(2) = 4/5xx6xx10^(4)=4.8xx10^(4)cal` Now heat converted to work `=Q_(1) - Q_(2) = 6.0xx10^(4)-4.8xx10^(4)=1.2xx10^(4)cal` Aliter: `eta = (T_1-T_2)/(T_1) = W/Q implies W = (Q(T_1-T_2))/(T_1)` `W = (6xx10^(4)[(227+273)-(273+127)])/((227+273))` `implies W = (6xx10^(4)xx100)/(500)=1.2xx10^(4)cal`. |
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