Question

An $AC$ circuit is shown in the figure. A dielectric slab is placed between the plates, then

• A. Brightness of bulb increases.
• B. Brightness of bulb decreases.
• C. Brightness of buld remains same.
• D. cannot say.

Answer 1

The correct option is A Brightness of bulb increases.

Because of inserting the dielectric, capacitance increases, hence Z $\downarrow ,$ and current through both L and R increases$\uparrow$.
So the bulb becomes more birighter.