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JEE Main 202330 JanuaryEvening Shift
Exam
JEE Main
Year
2023
Date
30 January
Shift
Evening Shift
Subject
Physics
Chapter
Thermodynamics

JEE Main 2023 · 30 January · Evening Shift · Physics · Thermodynamics

Given below are two statements : one is labelled as Assertion A and...

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : Efficiency of a reversible heat engine will be highest at –273°C– 273 ° C temperature of cold reservoir.

Reason R : The efficiency of Carnot’s engine depends not only on temperature of cold reservoir but it depends on the temperature of hot reservoir too and is given as η=(1−T2T1)η = \left(1 - \dfrac{{T}_{2}}{{T}_{1}}\right)

In the light of the above statements, choose the correct answer from the options given below :

Options

  1. AA is true but R is false
  2. BBoth A and R are true but R is NOT the correct explanation of A
  3. CA is false but R is true
  4. DBoth A and R are true and R is the correct explanation of A

Correct answer

D. Both A and R are true and R is the correct explanation of A

Step-by-step solution

As we know, η=1−TsinkTsource(maximum value ofη=1)⇒1=1−TsinkTsource⇒Tsink=0K=273°Cη = 1 - \dfrac{{T}_{sink}}{{T}_{source}}\left(\text{maximum value of}η = 1\right) ⇒ 1 = 1 - \dfrac{{T}_{sink}}{{T}_{source}} ⇒ {T}_{sink} = 0K = 273 ° C

Therefore, both A and R are true and R is the correct explanation of A.

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