HARD
KCET (UG)
IMPORTANT
Earn 100

A solid body of constant heat capacity 1 J -1 is being heated by keeping it in contact with reservoirs in two ways: (i) Sequentially keeping in contact with 2 reservoirs such that each reservoir supplies the same amount of heat. (ii) Sequentially keeping in contact with 8 reservoirs such that each reservoir supplies the same amount of heat. In both, cases the body is brought from initial temperature 100 K to final temperature 200 K . Entropy change of the body in the two cases respectively is: Note: This question was awarded as a bonus since temperatures were given in centigrade instead of in Kelvin. Proper corrections are made in the question to avoid it.

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Important Questions on Thermodynamics

HARD
KCET (UG)
IMPORTANT
One mole of each N2, O2 and 1/2 mole of H2 at 25oC and 1 atm pressure are mixed isothermally, the final total pressure being one atm. Calculate approx  Δ S.

n5=1.6 n2=0.7

 

EASY
KCET (UG)
IMPORTANT
Second law of thermodynamics is equivalent to which of the following statements?
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IMPORTANT

In any reversible process, the entropy of system and surroundings will

EASY
KCET (UG)
IMPORTANT
Entropy of the universe tends to be
EASY
KCET (UG)
IMPORTANT
A Carnot engine has the same efficiency between (i) 100 K and 500 K, (ii) T K and 900 K. The value of T is
MEDIUM
KCET (UG)
IMPORTANT
A Carnot freezer takes heat from water at 0oC inside it and rejects it to the room at a temperature of 27oC. The latent heat of ice is 336×103 Jkg-1. If 5kg of water at 0oC is converted into ice at 0oC by the freezer, then the energy consumed by the freezer is close to :
MEDIUM
KCET (UG)
IMPORTANT
A Carnot's engine works like a refrigerator between 250 K and 300 K. It receives 500 cal heat from the reservoir at a lower temperature. The amount of work done in each cycle to operate the refrigerator is,
EASY
KCET (UG)
IMPORTANT
Two carnot engines A and B are operated in series. The first one, A, receives heat at T1=600K and rejects to a reservoir at temperature T2. The second engine B receives heat rejected by the first engine and, in turn, rejects to a heat reservoir at T3=400K. Calculate the temperature T2 if the work outputs of the two engines are equal: