A light bulb and an inductor are connected in series to an AC source. After the switch is closed, an iron core is inserted in the inductor. The bulb brightness:
Options

Question

A light bulb and an inductor are connected in series to an AC source. After the switch is closed, an iron core is inserted in the inductor. The bulb brightness:

G1 Physics · Accepted Answer

Step 1: Inserting the core raises the coil inductance L. Step 2: Inductive reactance X(L) = ωL therefore increases. Step 3: With unchanged supply, current decreases and the bulb glows less brightly (option A). Final answer: (A) decreases.