First law of thermodynamics is a consequence of conservation of

Solution :
According to the first law of thermodynamics, when some quantity of heat $$\left( {dQ} \right)$$  is supplied to a system capable of doing external work, then the quantity of heat absorbed by the system $$\left( {dQ} \right)$$  is equal to the sum of the increase in the internal energy of the system $$\left( {dU} \right)$$  due to rise in temperature and the external work done by the system $$\left( {dQ} \right)$$  in expansion,
i.e. $$dQ = dU + dW$$
This law, which is basically the law of conservation of energy applies to every process in nature.