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A light bulb and an inductor coil are connected to an ac source through a key as shown in the figure below. The key is closed and after sometime an iron rod is inserted into the interior of the inductor. The glow of the light bulb
A
increases
B
decreases
C
remains unchanged
D
will fluctuate
Detailed Solution
Inserting an iron rod increases the inductance L (and hence the inductive reactance $X_L=\omega L$) of the coil, which increases the total impedance of the circuit, reducing the current and hence the glow (brightness) of the bulb.