Read the following paragraph and answer the questions :If heat is exchanged between a hot and cold object, the temperature of the cold object goes on increasing due to gain of energy and temperature of the hot object goes on decreasing due to loss of…

Answer: (a) From the hot object to the cold object; (b) the principle of heat exchange; (c) heat lost by the hot body = heat gained by the cold body.

(a) Heat flows from the hotter object to the colder object, because energy is transferred from a body at higher temperature to one at lower temperature. This continues till both reach the same temperature.

(b) The process teaches the principle of heat exchange (the principle of calorimetry). It is the basis of the method of mixtures used to measure specific heat capacity and latent heat.

(c) In an isolated system, no heat is lost to the surroundings, so the heat given out by the hot object is exactly equal to the heat taken in by the cold object:

\[Q_{\text{lost}} = Q_{\text{gained}}, \qquad m_1 c_1 (T_1 - T) = m_2 c_2 (T - T_2)\]