1 Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
\(\eta = 1 - \left( {\frac{{{T_{\sin k}}}}{{{T_{{\rm{source }}}}}}} \right)\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(1)\)
\(\eta = \frac{{\Delta Q}}{{\Delta W}}{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} \,\,\,\,{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} (2)\)
The efficiency of a Carnot engine does increase as the temperature of the sink decreases due to a larger temperature difference. However, the reason does not accurately explain this effect, as it "over-simplifies" the relationship by focusing only on the sink's temperature. So correct option is (2).
