In what process is the heat added entirely converted into internal energy of the system ?

Explanation

To determine the process in which the heat added to a system is entirely converted into the internal energy of that system, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the First Law of Thermodynamics**:
The first law of thermodynamics states that the change in internal energy (dU) of a system is equal to the heat added to the system (dQ) minus the work done by the system (dW). This can be expressed mathematically as:
\[
dQ = dU + dW
...