2. Questions Bank
  3. NEET
  4. Physics
  5. Thermometry, Calorimetry & Thermal Expansion

NEET Physics Thermometry, Calorimetry & Thermal Expansion Question Bank Mock Test - Thermal Properties of Matter

  • question_answer
    An electrically heated coil is immersed in a calorimeter containing 360 g of water at\[10{}^\circ C\]. The coil consumes energy at the rate of 90 W. The water equivalent of calorimeter and coil is 40 g. The temperature of water after 10 min is

    A) \[4.214{}^\circ C\]      

    B) \[42.14{}^\circ C\]

    C) \[30{}^\circ C\]           

    D) None of these

    Correct Answer: B

    Solution :

    [b] Energy supplied by the heater to the system in 10 min \[{{Q}_{1}}=P\times t=90J/s\times 10\times 60s\] \[=54000J=\frac{54000}{4.2}cal=12857cal\] Now if \[\theta \] is the final temperature of the system, energy absorbed by it to change its temperature from \[10{}^\circ C\]to \[\theta \] \[{}^\circ C\]is \[{{Q}_{2}}={{(ms\Delta T)}_{water}}+{{(ms\Delta T)}_{coil+calorimeter}}\] \[=360\times 1\times (\theta -10)+40(\theta -10)\] \[=400(\theta -10)\] According to problem, \[{{Q}_{1}}={{Q}_{2}}\] So \[12857=400(\theta -10)\]or \[\theta =42.14{}^\circ C\]


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