A capacitor stores 10mC charge when connected across a battery. When the gap between the plates is filled with a dielectric, a charge of 20mC flows through the battery. Find the dielectric constant of the dielectric.
Answer & explanation
Correct answer: option 3
In absence of dielectric Q = CV = 10μC
With dielectric , A charge of $20 \mu C$ flw from the battery hence total charge becomes $30\mu C$
$\Rightarrow Q'= kCV = 30\mu C$
$ k = \frac{Q'}{Q} = 3$