JEE Main Question Discussion



A mass of 50g of water in a closed vessel, with surroundings at a constant temperature takes 2 minutes to cool from 30’C to 25’C. A mass of 100g of another liquid in an identical vessel with identical surroundings takes the same time to cool from 30’C to 25’C. The specific heat of liquid is {water equivalent of vessel is 30g}

ANs. 0.5 kcal/kg


S.H.C. = Heat Energy / (mass of substance * change in temperature)

For water, SHC = 1, M = .05 , dT = 5
For the liquid, SHC = unknown, M = .1 , dT = 5

Use the formula to equate heat energies and get the answer.