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JEE Mains · Physics · STD 11 - 10.1, thermonetry,thermal expansion and calorimetry

Water of volume \(2\, L\) in a closed container is heated with a coil of \(1\,kW\). While water is heated, the container loses energy at a rate of \(160\, J/s\) . In how much time will the temperature of water rise from \(27\,^oC\) to \(77\,^oC\) ? (Specific heat of water is \(4.2\, kJ/kg\) and that of the container is negligible)

  1. A \(8\,min\, 20\, s\)
  2. B \(6\,min\, 2\, s\)
  3. C \(7\, min\)
  4. D \(14\, min\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(8\,min\, 20\, s\)

Step-by-step Solution

Detailed explanation

Fromquestion, In \(1\,sec\) heat gained by water \( = 1\,K\,W - 160J/s\) \( = 1000\,J/s - 160\,J/s\) \( = 840\,J/s\) Total heat required to raise the temperature of water \(\left( {volume\,2L} \right)\,from\,{27^ \circ }c\,to\,{77^ \circ }c\)…