An electric heater of power 100 W raises the temperature of 5 kg of a liquid from `25^(@)C` to `31^(@)C` in 2 minutes. Calculate the specific heat of the liquid.

How much heat energy is necessary to raise the temperature of 5 kg of water from 20 ^@ C " to " 100^@C ?

The heat produced on complete combustion of 20 g of a fuel could raise the temperature of 1.5 kg of water form 25^(@)C to 75^(@)C . Calculate the calorific value of the fuel if the specific heat capacity of water is 4.2 J g^(-1).^(@)C^(-1) . Assume that the heat absorbed by the container is negligible.

A liquid having mass m = 250 g is kept warm in a vessel by use of an electric heater. The liquid is maintained at 50^(@)C when the power supplied by heater is 30 watt and surrounding temperature is 20^(@)C . As the heater is switched off, the liquid starts cooling and it was observed that it took 10 second for temperature to fall down from 40^(@)C to 39.9^(@)C . Calculate the specific heat capacity of the liquid. Assume Newton’s law of cooling to be applicable.

An electric heater rated as (500 W and 200 V) raises the temperature of 1 kg water from 15^(@)C to its boiling point in 15 min. the heat effeciency of the heater is

Calculate the amount of heat required to raise the temperature of 5 g of iron from 25^(@)C "to" 75^(@)C . The specific heat capacity of iron is 0.45 J/g.