2. Solved Papers
  3. J & K CET Medical

J & K CET Medical J & K - CET Medical Solved Paper-2000

  • question_answer
    70 cal of heat are required to raise the temperature of 2 moles of an ideal gas at constant pressure from \[30{}^\circ C\] to \[35{}^\circ C\]. The amount of heat required in calories to raise the temperature of the same gas through the same range \[\left( 30{}^\circ C-35{}^\circ C \right)\] at constant volume is :

    A)  30 cal                                   

    B)  50 cal

    C)  370 cal                                 

    D)  90 cal

    Correct Answer: B

    Solution :

                    The heat required to raise the temperature of gas, at constant volume\[({{C}_{V}})\]is \[{{Q}_{V}}={{C}_{V}}\Delta T\]                               ...(i) and at constant pressure is \[{{Q}_{P}}={{C}_{P}}\Delta T\]                              ...(ii) Also,       \[\gamma =\frac{{{C}_{P}}}{{{C}_{V}}}\]                                 ...(iii) From Eqs. (i), (ii) and (iii), we get                 \[\frac{{{Q}_{V}}}{{{Q}_{P}}}=\frac{{{C}_{P}}}{{{C}_{V}}}=\frac{1}{\gamma }\] For a diatomic gas                 \[\gamma =\frac{7}{5}\] \[\therefore \]  \[{{Q}_{V}}=\frac{5}{7}\times 70=50\,cal\]


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