A heat engine has an efficiency of ${1 \over 6}$. When the temperature of sink is reduced by 62$^\circ$C, its efficiency get doubled. The temperature of the source is :
Solution
$\eta = 1 - {{{T_L}} \over {{T_H}}}$ ..... (i)<br><br>$$2\eta = 1 - {{({T_L} - 62)} \over {{T_H}}} = 1 - {{{T_L}} \over {{T_H}}} + {{62} \over {{T_H}}}$$<br><br>$$ \Rightarrow \eta = {{62} \over {{T_H}}} \Rightarrow {1 \over 6} = {{62} \over {{T_H}}} \Rightarrow {T_H} = 6 \times 62 = 372$$ K<br><br>In $^\circ$C $\Rightarrow$ 372 $-$ 273 = 99$^\circ$ C
About this question
Subject: Physics · Chapter: Thermodynamics · Topic: Second Law and Entropy
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