Correct answer: 11 H
The induced emf is given by Faraday's law: \( e = -L \frac{dI}{dt} \). Rearranging, \( L = \frac{e \cdot \Delta t}{\Delta I} \). Substituting \( e = 220 \text{ V}, \Delta t = 0.5 \text{ s}, \Delta I = 10 \text{ A} \), we get \( L = \frac{220 \cdot 0.5}{10} = 11 \text{ H} \).