A light bulb and an open coil inductor are connected to an ac source through a key as shown in Fig. The switch is closed and after sometime, an iron rod is inserted inot the interior of the inductor. The glow of the ligth bulb (a) increases (b) decreases (c) is unchanged as the iron is inserted. Give your answer with reasosns. What will be your answer if ac source is replaced by dc source ?

Explanation

Decreases, due to increase in inductive reactance.