Final answer:
The current in a circuit involving exponential decay cannot naturally reach 12i0 after starting from i0; it would decrease to 0.368i0 after one time constant and continue to decrease further.
Step-by-step explanation:
The question involves understanding the time-dependent behavior of current in a circuit, which involves the concept of exponential decay and the time constant (τ) of an RC (resistor-capacitor) or RL (resistor-inductor) circuit. At t = 0s, the current is given as i0. The current decreases to 0.368 after one time constant. Likewise, in subsequent time intervals of τ, the current will continue to fall to 0.368 of its previous value. To determine when the current is 12i0, we would need to solve an exponential equation representing the growth of the current over time. However, since current falls to 0.368 after the first time constant and continues to decrease, reaching 12 would not be possible unless there is some form of external influence or change in the circuit's configuration that would cause the current to increase instead of decrease.