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JEE Main 201912 AprilEvening Shift

Exam: JEE Main
Year: 2019
Date: 12 April
Shift: Evening Shift
Subject: Physics
Chapter: Thermodynamics

JEE Main 2019 · 12 April · Evening Shift · Physics · Thermodynamics

A Carnot engine has an efficiency of (1)/(6) . When the temperature...

A Carnot engine has an efficiency of

\dfrac{1}{6} .

When the temperature of the sink is reduced by

62℃

, its efficiency is doubled. The temperatures of the source and the sink are, respectively,

Options

A $124℃, 62℃$
B $37℃\text{, 99}℃$
C $\text{99}℃, 37℃$
D $\text{62}℃, 124℃$

Correct answer

B. $37℃\text{, 99}℃$

Step-by-step solution

η = 1 - \dfrac{{T}_{sink}}{{T}_{source}}

\dfrac{1}{6} = 1 - \dfrac{{T}_{1}}{{T}_{2}}

….(1)

\dfrac{1}{3} = 1 - \dfrac{{T}_{1} - 62}{{T}_{2}}

….(2)
From equation (1) and (2)

{T}_{2} = 372Kor99℃

And

{T}_{1} = 310Kor37℃

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