Which of the following processes exhibits that Δ U = Q_v ?

According to the first law of thermodynamics, the change in internal energy is given by $\Delta U = Q + W$.

The work done by the system is $W = -P \Delta V$.

For an isochoric process, the volume remains constant, which means $\Delta V = 0$.

Therefore, the work done $W = 0$.

Substituting this into the first law equation, we get $\Delta U = Q$.

Since the heat is exchanged at constant volume, it is denoted as $Q_v$. Thus, $\Delta U = Q_v$ for an isochoric process.

Answer: Isochoric