Q. A capacitor and an inductance coil are connected in separate AC circuits with a bulb glowing in both the circuits. The bulb glows more brightly when
A) An iron rod is introduced into the inductance coil
B) The number of turns in the inductance coil is increased
C) Separation between the plates of the capacitor is increased
D) A dielectric is introduced into the gap between the plates of the capacitor
Explanation
(d) Current$,\ i = \frac{V}{\sqrt{R^{2} + X_{C}^{2}}}$
If a dielectric is introduced into the gap between the plates of capacitor. Its capacitance will increase and hence, impedance of the circuit will decrease. Thus, current and hence brightness of the bulb increase.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.