Question

The transfer of thermal energy to a substance always result an increase in temperature ? true to be always ? explain further why !

Answer 1

No, the transfer of thermal energy to a system need not always results in increase in temperature.

As an example, take certain quanty of ice at 0 degree celsius. when thermal energy is supplied, ice begins to melt into water at 0 degree celsius. During the melting process, energy gven to the ice completely used to melt the ice and there is no change in internal energy. The temperature of a system can increase only if there is an increase in internal energy.

From the 1st law of thermodynamics, dQ = dU + dW. if a process is carried out in such a way that increase in internal energy dU = 0 then there will be no rise in temperature.