Answer
$V_L = 10~V$
Work Step by Step
In part (d), we found that the potential difference across $R_2$ is zero.
According to the loop rule, the sum of the potential difference across the battery, the inductor, and $R_2$ must be zero.
Since the potential difference across the battery is $10~V$, the magnitude of the potential difference across the inductor must be $10~V$
Therefore:
$V_L = 10~V$
