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Heat and Thermodynamics question

2025 · 28 Jan · Shift 1 · Q70
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Heat and Thermodynamics question

2025 · 28 Jan · Shift 1 · Q70

JEE MainPhysicsHeat and ThermodynamicsMCQ+4 / −1
A Carnot engine (E)(\mathrm{E})(E) is working between two temperatures 473 K and 273 K . In a new system two engines - engine E1E_1E1​ works between 473 K to 373 K and engine E2E_2E2​ works between 373 K to 273 K . If η12,η1\eta_{12}, \eta_1η12​,η1​ and η2\eta_2η2​ are the efficiencies of the engines E,E1E, E_1E,E1​ and E2E_2E2​, respectively, then
  1. A
    η12=η1η2\eta_{12}=\eta_1 \eta_2η12​=η1​η2​
  2. B
    η12=η1+η2\eta_{12}=\eta_1+\eta_2η12​=η1​+η2​
  3. C
    η12≥η1+η2\eta_{12} \geq \eta_1+\eta_2η12​≥η1​+η2​
  4. D
    η12<η1+η2\eta_{12}\lt \eta_1+\eta_2η12​<η1​+η2​
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