Two litre of water at initial temperature of 27^ C is heated by a heater of power 1 kW . If the lid of kettle is opened, then heat is lost at the constant rate of 160 ~J / s . Find, the time required to raise the temperature of water to 77^

Question

Two litre of water at initial temperature of 27^ C is heated by a heater of power 1 kW . If the lid of kettle is opened, then heat is lost at the constant rate of 160 ~J / s . Find, the time required to raise the temperature of water to 77^ C with the lid open (specific heat of water 4.2 ~kJ / kg )

Quantrex Academy · Accepted Answer

Correct answer: C. 8 min 20 s

aligned & Rate of heat gain & =1000-160=840 ~J / s & Required time aligned Ans is 8 min 20 s

Two litre of water at initial temperature of 27^ C is heated by a heater of power 1 kW . If the lid of kettle is opened, then heat is lost at the constant rate of 160 ~J / s . Find, the time required to raise the temperature of water to 77^ C with the lid open (specific heat of water 4.2 ~kJ / kg )

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