MCQ
For a heat engine operating between temperatures $t _1{ }^{\circ} C$ and $t _2{ }^{\circ} C$, its efficiency will be______.
- A$`("t"_1 - "t"_2)/"t"_2`$
- ✓$`("t"_1 - "t"_2)/("t"_1 + 273)`$
- C$`1 - "t"_2/"t"_1`$
- D$`"t"_1/"t"_2`$
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( l cal = 4.2 J)
