Question

An air cored coil l and a bulb b are connected in series to the ac mains. the bulb glows with some brightness. how would the glow of the bulb change if an iron rod were inserted in the coil? give reasons in support of your answer.

Answer 1

The brightness of the bulb will reduce when rod is inserted.
The insertion of the iron rod increases the inductance (L) of the coil. XL=2piFL.Increase Of XL reduces current

Answer 2

When the iron coil is removed, the current flow will be at its maximum and the bulb will glow brightly; when it is inserted, there will be an induction current effect and the bulb will glow with less intensity. A magnetic field is created when the current passes through an inductor and it opposes the current flow.