Answer:
heat input minus the work done on the gas.
Step-by-step explanation:
According to the first law of thermodynamics, the increase in the internal energy during any process involving a gas equals to the heat input minus the work done on the gas.
we know that from the First law for process
heat input= change in internal energy+ work done
dQ= dU+ dW
this implies
dU= dQ- dW
So we write the above statement