If the energy input to a Carnot engine is thrice the work it performs then, the fraction of energy rejected…

If the energy input to a Carnot engine is thrice the work it performs then, the fraction of energy rejected to the sink is
  1. $\frac{1}{3}$
  2. $\frac{1}{4}$
  3. $\frac{2}{5}$
  4. $\frac{2}{3}$

Solution

Efficiency $\eta=\frac{\mathrm{W}_{\text {output }}}{\text { Heat }_{\text {input }}}=\frac{\mathrm{w}}{3 \mathrm{w}}=\frac{1}{3}$
$\eta=1-\frac{\mathrm{Q}_{2}}{\mathrm{Q}_{1}}=\frac{1}{3} \quad \therefore \frac{\mathrm{Q}_{2}}{\mathrm{Q}_{1}}=\frac{2}{3}$ .

Asked in: JEE-TOPICTESTS-CHEMISTRY

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