Question

A bulb and a capacitor are connected in series across an ac supply. A dielectric is then placed between the plates of the capacitor. The glow of the bulb: 

(1) increases 

(2) remains same 

(3) becomes zero 

(4) decreases

Answer 1

Correct option is : (1) increases  

\( Z=\sqrt{R^{2}+X_{C}^{2}} \ \&\ X_{C}=\frac{1}{W C} \)

due to dielectric

\(\mathrm{C} \uparrow \Rightarrow \mathrm{X}_{\mathrm{C}} \downarrow \Rightarrow \mathrm{Z} \downarrow\)

So, current increases & thus bulb will glow more brighter.