NEET Physics Thermodynamics Questions Solved


A reversible engine converts one-sixth of the heat input into work. When the temperature of the sink is reduced by 62°C, the efficiency of the engine is doubled. The temperatures of the source and sink are -

(1) 80°C, 37°C

(2) 95°C, 28°C

(3) 90°C, 37°C

(4) 99°C, 37°C

Concept Videos :-

#48 | Introduction to Heat Engine
#49 | Solved Example: 23
#50 | Refrigerator
#52 | Carnot Engine
#53 | Carnot Cycle
#54 | Solved Example: 24
#55 | Solved Example: 25

Concept Questions :-

Heat engine and refrigerator

(4) Initially η=1T2T1=WQ=16  ...(i)

Finally η'=1T2'T1=1(T262)T1=1T2T1+62T1

=η+62T1 ....(ii)

It is given that η'=2η. Hence solving equation (i) and (ii)

T1=372K=99°C and T2=310K=37°C

Difficulty Level:

  • 7%
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  • 52%
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