JEE Main2014PhysicsThermodynamicsActual
A Carnot engine absorbs 1000 ~J of heat energy from a reservoir at 127^ C and rejects 600 ~J of heat energy during each cycle. The efficiency of engine and temperature of sink will be:
Options
- A20 % and -43^ C
- B40 % and -33^ C
- C50 % and -20^ C
- D70 % and -10^ C
Correct answer
B. 40 % and -33^ C
Step-by-step solution
Given: Q ₁=1000 ~J aligned & Q ₂=600 ~J & ~T ₁=127^ C =400 ~K & ~T ₂=? & =? aligned Efficiency of carnot engine, aligned & = W Q₁ 100 % & or, = Q₂-Q₁ Q₁ 100 % aligned or, = Q ₂- Q ₁ Q ₁ 100 % or, = 1000-600 1000 100 % =40 % Now, for carnot cycle Q ₂ Q ₁ = T ₂ ~T ₁ aligned & 600 1000 = T ₂ 400 & ~T ₂= 600 400 1000 =240 ~K =240-273 & T ₂=-33^ C aligned