Heat Engines and Refrigerators: JEE Main previous year questions.

• Carnot Efficiency LimitOpenRepeated15 · 68%68%3/8762
  • 8 Apr ’23 S2 · Q34
    Work done by a Carnot engine operating between temperatures $127^\circ$C and $27^\circ$C is 2 kJ. The amount of heat transferred to the…

    easySingle correctAsked the year before

  • 12 Apr ’23 S1 · Q38
    An engine operating between the boiling and freezing points of water will have A. efficiency more than 27%. B. efficiency less than the…

    mediumOtherAsked the year before

  • 25 Jul ’22 S2 · Q45
    Let $\eta_1$ is the efficiency of an engine at $\mathrm{T_1}$ = 447°C and $\mathrm{T_2}$ = 147°C while $\eta_2$ is the efficiency at…

    easySingle correctAsked the year before

  • 28 Jul ’22 S1 · Q37
    A Carnot engine has efficiency of 50%. If the temperature of sink is reduced by $40^\circ$C, its efficiency increases by 30%. The…

    mediumSingle correctAsked the year before

  • 30 Jul ’22 S2 · Q7
    A Carnot engine is operating between the two reservoirs of temperature 227 $^\circ$C and 127 $^\circ$C respectively. If the engine…

    easySingle correctAsked the year before

  • 24 Jun ’22 S1 · Q47
    A Carnot engine whose heat sinks at $27^\circ$C, has an efficiency of 25%. By how many degrees should the temperature of the source be…

    mediumSingle correctAsked the year before

  • 24 Jun ’22 S2 · Q35
    A Carnot engine takes 5000 kcal of heat from a reservoir at $727^{\circ}C$ and gives heat to a sink at $127^{\circ}C$. The work done by…

    easySingle correctAsked the year before

  • 26 Jun ’22 S1 · Q37
    The efficiency of a Carnot's engine, working between steam point and ice point, will be :

    easySingle correctAsked the year before

  • 3 Aug ’21 S1 · Q5
    A carnot engine working at source temperature 400 $K$, takes 500 $J$ heat from the source and rejects 300 $J$ to sink. What is the…

    easySingle correctNew idea

  • 27 Aug ’21 S2 · Q26
    A heat engine operates between a cold reservoir at temperature $T_2=400$ K and a hot reservoir at temperature $T_1$. It takes 300 J of…

    easyNumerical valueNew idea

  • 31 Aug ’21 S1 · Q15
    A reversible engine has an efficiency of $\frac{1}{4}$. If the temperature of the sink is reduced by $58^\circ$C, its efficiency becomes…

    mediumSingle correctNew idea

  • 25 Feb ’21 S2 · Q25
    A reversible heat engine converts one-fourth of the heat input into work. When the temperature of the sink is reduced by 52 K, its…

    mediumNumerical valueNew idea

  • 25 Jul ’21 S2 · Q9
    A heat engine has an efficiency of $\frac{1}{6}$. When the temperature of sink is reduced by 62°C, its efficiency get doubled. The…

    mediumSingle correctNew idea

  • 16 Mar ’21 S2 · Q26
    For an ideal heat engine, the temperature of the source is $127^\circ$C. In order to have 60% efficiency the temperature of the sink…

    easyNumerical valueNew idea

  • 17 Mar ’21 S1 · Q3
    A Carnot's engine working between 400 K and 800 K has a work output of 1200 J per cycle. The amount of heat energy supplied to the engine…

    easySingle correctNew idea

• Carnot Engines in SeriesOpen1 · 5%5%1/8
• Carnot Heat-Temperature RatioOpen1 · 5%5%1/8
• Carnot Refrigerator COP via TemperaturesOpen1 · 5%5%1/8
• Efficiency and COP ConversionOpen1 · 5%5%1/8
• Heat Engine EfficiencyOpen1 · 5%5%1/8
• Non-Carnot Cycle EfficiencyOpen1 · 5%5%1/8
• Refrigerator COPOpen1 · 5%5%1/8

Squares are the 8 years with analysed shifts, 2017 to 2026. A number is the questions that year when there is more than one; the shade is scaled to one shift, so a year with more analysed shifts (1 to 24 a year) does not look darker. Share is of the level above.