Question

An iron cored coil is connected in series with an electric bulb, with an AC source, as shoen in figure. As the iron piece is taken out of the coil, how will tthe brightness of bulb challenge ?

Answer 1

As the iron rod is taken out of the coil, the self-inductance of the coil decreases, the impedance of circuit decreases, hence current increases. So, power consumed (and hence brightness of bulb) by bulb increases.