a b c d

c

$\text{ Resistance of the lamp is } R = \frac{V}{I} = \frac{80}{10} = 8A $ $ \text{when Voltage becomes 220V , then for 10A current impedance } = 22\Omega$ $ Z^2 = {R^2 + \omega^2L^2} $ $ L = \sqrt{\frac{Z^2 - R^2}{4\pi^2f^2}} = 0.065H$