2. Sample Papers
  3. KVPY

KVPY Sample Paper KVPY Stream-SX Model Paper-20

  • question_answer
    A system undergoes a cycle consisting of three processes.
    Process involved are listed as,
    process \[\Delta Q\,(kJ)\] \[\Delta W\,(kJ)\] \[\Delta U\,(kJ)\]
    \[1\to 2\] \[a\] \[100\] \[-100\]
    \[2\to 3\] \[b\] \[-\,50\] \[c\]
    \[3\to 4\] \[100\] \[d\] \[-\,200\]
    Values of a, b, c and d, respectively are

    A) \[200\text{ }kJ,\text{ }50\text{ }kJ,\text{ }100\text{ }kJ,\text{ }300\text{ }kJ\]

    B) \[200\text{ }kJ,\text{ }50\text{ }kJ,\text{ }300\text{ }kJ,\text{ }100\text{ }kJ\]

    C) \[50\text{ }kJ,\text{ }100\text{ }kJ,\text{ }200\text{ }kJ,\text{ }300\text{ }kJ\]

    D) \[300\text{ }kJ,\text{ }200\text{ }kJ,\text{ }200\text{ }kJ,\text{ }50\text{ }kJ\]

    Correct Answer: A

    Solution :

    From first law of thermodynamics,
    we have, \[\Delta Q-\Delta W=\Delta E\]
    Applied to process \[1\to 2\] we get
    \[a-100=100\Rightarrow a=200KJ\]
    For process \[3\to 1\],
    \[100-d=-200\]
    \[d=300KJ\]
    For entire cycle, \[\sum Q=\sum W\]\[\Rightarrow \,\,\,200+b+100=350\Rightarrow b=50KJ\]
    For a cyclic process, \[\sum \Delta U=0\]\[\Rightarrow 100+c-200=0\]\[\Rightarrow \,\,\,\,\,\,\,\,\,\,c=100KJ\]


You need to login to perform this action.
You will be redirected in 3 sec spinner